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  4. Windows XP Convert SystemDrive Variable e.g. %SystemDrive% - into equivelant C++ code

Windows XP Convert SystemDrive Variable e.g. %SystemDrive% - into equivelant C++ code

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  • D David Crow

    How exactly would that function return the desired information?

    "One man's wage rise is another man's price increase." - Harold Wilson

    "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

    "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

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    Victor Nijegorodov
    wrote on last edited by
    #12

    AS you suggested: call any of the SHGetFolderPath(), ... with CSIDL_WINDOWS and then pass the returned path (say, windowsDir) into PathGetDriveNumber:

    WCHAR letter = L'A' + PathGetDriveNumberW(windowsDir);

    D 1 Reply Last reply
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    • V Victor Nijegorodov

      AS you suggested: call any of the SHGetFolderPath(), ... with CSIDL_WINDOWS and then pass the returned path (say, windowsDir) into PathGetDriveNumber:

      WCHAR letter = L'A' + PathGetDriveNumberW(windowsDir);

      D Offline
      D Offline
      David Crow
      wrote on last edited by
      #13

      But the return value from SHGetKnownFolderPath() already contains the system's drive letter. There's no need to pass that path to PathGetDriveNumber(), have it return a number, and then convert that number back into a drive letter that was already obtained.

      "One man's wage rise is another man's price increase." - Harold Wilson

      "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

      "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

      V 2 Replies Last reply
      0
      • D David Crow

        But the return value from SHGetKnownFolderPath() already contains the system's drive letter. There's no need to pass that path to PathGetDriveNumber(), have it return a number, and then convert that number back into a drive letter that was already obtained.

        "One man's wage rise is another man's price increase." - Harold Wilson

        "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

        "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

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        Victor Nijegorodov
        wrote on last edited by
        #14

        Yes, i know it. It was just a proposal to use an API rather than to search for a letter in the returned path ... :)

        D 1 Reply Last reply
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        • D David Crow

          But the return value from SHGetKnownFolderPath() already contains the system's drive letter. There's no need to pass that path to PathGetDriveNumber(), have it return a number, and then convert that number back into a drive letter that was already obtained.

          "One man's wage rise is another man's price increase." - Harold Wilson

          "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

          "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

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          Victor Nijegorodov
          wrote on last edited by
          #15

          Once more, my reply was not for you, it was just for the OP... ;) Sorry, if I put it in a wrong place! :|

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          • V Victor Nijegorodov

            Yes, i know it. It was just a proposal to use an API rather than to search for a letter in the returned path ... :)

            D Offline
            D Offline
            David Crow
            wrote on last edited by
            #16

            Victor Nijegorodov wrote:

            ...rather than to search for a letter in the returned path

            Search for something that's always in position 0?

            "One man's wage rise is another man's price increase." - Harold Wilson

            "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

            "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

            V 1 Reply Last reply
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            • D David Crow

              Victor Nijegorodov wrote:

              ...rather than to search for a letter in the returned path

              Search for something that's always in position 0?

              "One man's wage rise is another man's price increase." - Harold Wilson

              "Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons

              "You can easily judge the character of a man by how he treats those who can do nothing for him." - James D. Miles

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              V Offline
              Victor Nijegorodov
              wrote on last edited by
              #17

              :thumbsup: ;)

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              • V Victor Nijegorodov

                AS you suggested: call any of the SHGetFolderPath(), ... with CSIDL_WINDOWS and then pass the returned path (say, windowsDir) into PathGetDriveNumber:

                WCHAR letter = L'A' + PathGetDriveNumberW(windowsDir);

                J Offline
                J Offline
                jackngill
                wrote on last edited by
                #18

                Hi folks thanks for the input, PathGetDriveNumberA function Searches a path for a drive letter within the range of 'A' to 'Z' and returns the corresponding drive number. Syntax

                int PathGetDriveNumberA(
                LPCSTR pszPath
                );

                Parameters pszPath Type: LPCTSTR A pointer to a null-terminated string of maximum length MAX_PATH that contains the path to be searched. Return value Type: int Returns 0 through 25 (corresponding to 'A' through 'Z') if the path has a drive letter, or -1 otherwise. Remarks Note The shlwapi.h header defines PathGetDriveNumber as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes. Taken from: PathGetDriveNumberA function (shlwapi.h) - Win32 apps | Microsoft Docs[^] does this help in any way? Regards Jackngill

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                • J jackngill

                  Hi folks thanks for the input, PathGetDriveNumberA function Searches a path for a drive letter within the range of 'A' to 'Z' and returns the corresponding drive number. Syntax

                  int PathGetDriveNumberA(
                  LPCSTR pszPath
                  );

                  Parameters pszPath Type: LPCTSTR A pointer to a null-terminated string of maximum length MAX_PATH that contains the path to be searched. Return value Type: int Returns 0 through 25 (corresponding to 'A' through 'Z') if the path has a drive letter, or -1 otherwise. Remarks Note The shlwapi.h header defines PathGetDriveNumber as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes. Taken from: PathGetDriveNumberA function (shlwapi.h) - Win32 apps | Microsoft Docs[^] does this help in any way? Regards Jackngill

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                  Victor Nijegorodov
                  wrote on last edited by
                  #19

                  jackngill wrote:

                  does this help in any way?

                  Yes. However, I'd use another way (more simple). See my post here: [Re: Windows XP Convert SystemDrive Variable e.g. %SystemDrive% - into equivelant C++ code - C / C++ / MFC Discussion Boards](https://www.codeproject.com/Messages/5747207/Re-Windows-XP-Convert-SystemDrive-Variable-e-g-Sys)

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                  • V Victor Nijegorodov

                    Did you try [GetEnvironmentVariable function (winbase.h) - Win32 apps | Microsoft Docs](https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-getenvironmentvariable) ?

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                    J Offline
                    jackngill
                    wrote on last edited by
                    #20

                    Hi Victor Many thanks can I take a further liberty in answering your question with yet another question? Your "?" - Did you try GetEnvironmentVariable function (winbase.h) - Win32 apps | Microsoft Docs ? Can I answer with: Is there (of some Kind like for instance Emu8086) that would be able to run C++ code to check if it works & possibly feedback errors compatable that is compatable with XP as my skills in C++ are shall we say are very sadly lacking as suggested in my 1st post. I know what I want to do but don't know how to get there. The short answer is no sorry! I have been researching further & I have found this snippet of code from (To reveal the source click on the link below) C++/CLI Code Snippet - Access current environment directories and logical drives[^] which states this

                    // Gets the home drive - %HOMEDRIVE% (possible HOMEDRIVE is related to Windows7)
                    // Typical value - C:
                    Console::WriteLine("Get Environment Variable: Home Drive " + Environment::GetEnvironmentVariable("HOMEDRIVE"));

                    However Line 15 (the last 2 lines) is all one line & it states Writeline which infers output to console? Then could Homedrive be called/injected into this line in the first post

                    SetSfcFileException(0, L"c:\\windows\\system32\\calc.exe",-1);

                    like this:

                    SetSfcFileException(0, L"HOMEDRIVE:\\windows\\system32\\calc.exe",-1);

                    I am assuming I would need new headers & would need to know where to insert the code. I am assuming prior to the execution of the code in the 1st post I made (which I did not write), because once the code is executed within the C++ it would remain memory resident to access later to envoke the HOMEDRIVE system variable. Hope I am not blowing smoke here just a theory? P.S. Is the C++ code in post 1 for windows or commandline as the above code I think is for commandline, I wouldn't have thought mixing code from two standpoints would Not be Good? All the best, Jackngill

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                    • J jackngill

                      Hi Victor Many thanks can I take a further liberty in answering your question with yet another question? Your "?" - Did you try GetEnvironmentVariable function (winbase.h) - Win32 apps | Microsoft Docs ? Can I answer with: Is there (of some Kind like for instance Emu8086) that would be able to run C++ code to check if it works & possibly feedback errors compatable that is compatable with XP as my skills in C++ are shall we say are very sadly lacking as suggested in my 1st post. I know what I want to do but don't know how to get there. The short answer is no sorry! I have been researching further & I have found this snippet of code from (To reveal the source click on the link below) C++/CLI Code Snippet - Access current environment directories and logical drives[^] which states this

                      // Gets the home drive - %HOMEDRIVE% (possible HOMEDRIVE is related to Windows7)
                      // Typical value - C:
                      Console::WriteLine("Get Environment Variable: Home Drive " + Environment::GetEnvironmentVariable("HOMEDRIVE"));

                      However Line 15 (the last 2 lines) is all one line & it states Writeline which infers output to console? Then could Homedrive be called/injected into this line in the first post

                      SetSfcFileException(0, L"c:\\windows\\system32\\calc.exe",-1);

                      like this:

                      SetSfcFileException(0, L"HOMEDRIVE:\\windows\\system32\\calc.exe",-1);

                      I am assuming I would need new headers & would need to know where to insert the code. I am assuming prior to the execution of the code in the 1st post I made (which I did not write), because once the code is executed within the C++ it would remain memory resident to access later to envoke the HOMEDRIVE system variable. Hope I am not blowing smoke here just a theory? P.S. Is the C++ code in post 1 for windows or commandline as the above code I think is for commandline, I wouldn't have thought mixing code from two standpoints would Not be Good? All the best, Jackngill

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                      Victor Nijegorodov
                      wrote on last edited by
                      #21

                      jackngill wrote:

                      I have been researching further & I have found this snippet of code from (To reveal the source click on the link below) C++/CLI Code Snippet - Access current environment directories and logical drives[^]

                      The sample from CPP-CLI source has nothing to do with the native C++ code that you seem to be using! Try this:

                      TCHAR buffer[30] = {0};
                      if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                      {
                      TCHAR path[MAX_PATH] = {0};
                      _stprintf(path, _T("%s\\windows\\system32\\calc.exe"), buffer);
                      TRACE(path); // just to be sure it is what we supposed...
                      SetSfcFileException(0, path, -1);
                      }

                      J 1 Reply Last reply
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                      • V Victor Nijegorodov

                        jackngill wrote:

                        I have been researching further & I have found this snippet of code from (To reveal the source click on the link below) C++/CLI Code Snippet - Access current environment directories and logical drives[^]

                        The sample from CPP-CLI source has nothing to do with the native C++ code that you seem to be using! Try this:

                        TCHAR buffer[30] = {0};
                        if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                        {
                        TCHAR path[MAX_PATH] = {0};
                        _stprintf(path, _T("%s\\windows\\system32\\calc.exe"), buffer);
                        TRACE(path); // just to be sure it is what we supposed...
                        SetSfcFileException(0, path, -1);
                        }

                        J Offline
                        J Offline
                        jackngill
                        wrote on last edited by
                        #22

                        Hi Victor, Sorry about the prior code snippet apologies. I have copied your code and ran it here: https://www.onlinegdb.com/online_c++_compiler[^] Unfortunately it came up with a few errors: Compilation failed due to following error(s). main.cpp:1:1: error: ‘TCHAR’ does not name a type TCHAR buffer[30] = {0}; ^~~~~ main.cpp:2:5: error: expected unqualified-id before ‘if’ if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer))) ^~ Do these error codes mean anything to you? Best Regards David

                        V 1 Reply Last reply
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                        • J jackngill

                          Hi Victor, Sorry about the prior code snippet apologies. I have copied your code and ran it here: https://www.onlinegdb.com/online_c++_compiler[^] Unfortunately it came up with a few errors: Compilation failed due to following error(s). main.cpp:1:1: error: ‘TCHAR’ does not name a type TCHAR buffer[30] = {0}; ^~~~~ main.cpp:2:5: error: expected unqualified-id before ‘if’ if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer))) ^~ Do these error codes mean anything to you? Best Regards David

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                          V Offline
                          Victor Nijegorodov
                          wrote on last edited by
                          #23

                          I have no idea what compiler you are using... If you compile it as UNICODE then replace TCHAR with wchar_t, _T() macro - with L, and _stprintf - with swprintf. Besides, learn using Google to fast search for such types of errors...

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                          • V Victor Nijegorodov

                            I have no idea what compiler you are using... If you compile it as UNICODE then replace TCHAR with wchar_t, _T() macro - with L, and _stprintf - with swprintf. Besides, learn using Google to fast search for such types of errors...

                            J Offline
                            J Offline
                            jackngill
                            wrote on last edited by
                            #24

                            Hi Victor, I am using online compiler as I am not setup to compile programs see link here: https://www.onlinegdb.com/online_c++_compiler[^] The file is temp called main.cpp enter the code and depress run small dialogue box at the bottom of the screen generates errors with indicators like with exchanged code as you suggested:

                            Compilation failed due to following error(s). main.cpp:1:8: error: expected unqualified-id before ‘,’ token
                            wchar_t**,** _T() buffer[30] = {0};
                            ^
                            main.cpp:1:15: error: expected initializer before ‘buffer’
                            wchar_t, _T() buffer[30] = {0};
                            ^~~~~~
                            main.cpp:2:5: error: expected unqualified-id before ‘if’
                            if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                            ^~

                            For this:

                            wchar_t, _T() buffer[30] = {0};
                            if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                            {
                            wchar_t, _T() path[MAX_PATH] = {0};
                            swprintf(path, _T("%s\windows\system32\calc.exe"), buffer);
                            TRACE(path); // just to be sure it is what we supposed...
                            SetSfcFileException(0, path, -1);
                            }

                            Could not find macro - with L in your code. I will research further error codes on WWW & get back to you Best Regards David

                            V 1 Reply Last reply
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                            • J jackngill

                              Hi Victor, I am using online compiler as I am not setup to compile programs see link here: https://www.onlinegdb.com/online_c++_compiler[^] The file is temp called main.cpp enter the code and depress run small dialogue box at the bottom of the screen generates errors with indicators like with exchanged code as you suggested:

                              Compilation failed due to following error(s). main.cpp:1:8: error: expected unqualified-id before ‘,’ token
                              wchar_t**,** _T() buffer[30] = {0};
                              ^
                              main.cpp:1:15: error: expected initializer before ‘buffer’
                              wchar_t, _T() buffer[30] = {0};
                              ^~~~~~
                              main.cpp:2:5: error: expected unqualified-id before ‘if’
                              if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                              ^~

                              For this:

                              wchar_t, _T() buffer[30] = {0};
                              if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                              {
                              wchar_t, _T() path[MAX_PATH] = {0};
                              swprintf(path, _T("%s\windows\system32\calc.exe"), buffer);
                              TRACE(path); // just to be sure it is what we supposed...
                              SetSfcFileException(0, path, -1);
                              }

                              Could not find macro - with L in your code. I will research further error codes on WWW & get back to you Best Regards David

                              V Offline
                              V Offline
                              Victor Nijegorodov
                              wrote on last edited by
                              #25

                              jackngill wrote:

                              Compilation failed due to following error(s). main.cpp:1:8: error: expected unqualified-id before ‘,’ token
                              wchar_t**,** _T() buffer[30] = {0};
                              ^
                              main.cpp:1:15: error: expected initializer before ‘buffer’
                              wchar_t, _T() buffer[30] = {0};
                              ^~~~~~
                              main.cpp:2:5: error: expected unqualified-id before ‘if’
                              if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                              ^~

                              For this:

                              wchar_t, _T() buffer[30] = {0};
                              if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                              {
                              wchar_t, _T() path[MAX_PATH] = {0};
                              swprintf(path, _T("%s\windows\system32\calc.exe"), buffer);
                              TRACE(path); // just to be sure it is what we supposed...
                              SetSfcFileException(0, path, -1);
                              }

                              What the abracadabra you wrote? :thumbsdown: Try

                              wchar_t buffer[30] = {0};
                              if (::GetEnvironmentVariable(L"SYSTEMDRIVE", buffer, 30))
                              {
                              wchar_t path[MAX_PATH] = {0};
                              swprintf(path, L"%s\windows\system32\calc.exe", buffer);
                              TRACE(path); // just to be sure it is what we supposed...
                              SetSfcFileException(0, path, -1);
                              }

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                              • V Victor Nijegorodov

                                jackngill wrote:

                                Compilation failed due to following error(s). main.cpp:1:8: error: expected unqualified-id before ‘,’ token
                                wchar_t**,** _T() buffer[30] = {0};
                                ^
                                main.cpp:1:15: error: expected initializer before ‘buffer’
                                wchar_t, _T() buffer[30] = {0};
                                ^~~~~~
                                main.cpp:2:5: error: expected unqualified-id before ‘if’
                                if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                                ^~

                                For this:

                                wchar_t, _T() buffer[30] = {0};
                                if (::GetEnvironmentVariable(_T("SYSTEMDRIVE"), buffer, _countof(buffer)))
                                {
                                wchar_t, _T() path[MAX_PATH] = {0};
                                swprintf(path, _T("%s\windows\system32\calc.exe"), buffer);
                                TRACE(path); // just to be sure it is what we supposed...
                                SetSfcFileException(0, path, -1);
                                }

                                What the abracadabra you wrote? :thumbsdown: Try

                                wchar_t buffer[30] = {0};
                                if (::GetEnvironmentVariable(L"SYSTEMDRIVE", buffer, 30))
                                {
                                wchar_t path[MAX_PATH] = {0};
                                swprintf(path, L"%s\windows\system32\calc.exe", buffer);
                                TRACE(path); // just to be sure it is what we supposed...
                                SetSfcFileException(0, path, -1);
                                }

                                J Offline
                                J Offline
                                jackngill
                                wrote on last edited by
                                #26

                                The only error now being reported back is this one by the way sorry for the gobble-de-gook code must have cut & paste wrong. main.cpp:2:1: error: expected unqualified-id before ‘if’ if (::GetEnvironmentVariable(L"SYSTEMDRIVE", buffer, 30)) ^~ "If" for some reason is proving a problem but only one error repoted though encouraging it is under the input tab on the compiler. Perhaps an if/else might work? Best Regards, David

                                V 1 Reply Last reply
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                                • J jackngill

                                  The only error now being reported back is this one by the way sorry for the gobble-de-gook code must have cut & paste wrong. main.cpp:2:1: error: expected unqualified-id before ‘if’ if (::GetEnvironmentVariable(L"SYSTEMDRIVE", buffer, 30)) ^~ "If" for some reason is proving a problem but only one error repoted though encouraging it is under the input tab on the compiler. Perhaps an if/else might work? Best Regards, David

                                  V Offline
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                                  Victor Nijegorodov
                                  wrote on last edited by
                                  #27

                                  Are you banned by [Google](https://www.google.com/search?q=error%3A+expected+unqualified-id+before+‘if’&oq=error%3A+expected+unqualified-id+before+‘if’&aqs=chrome..69i57j69i58&sourceid=chrome&ie=UTF-8)?

                                  J 1 Reply Last reply
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                                  • V Victor Nijegorodov

                                    Are you banned by [Google](https://www.google.com/search?q=error%3A+expected+unqualified-id+before+‘if’&oq=error%3A+expected+unqualified-id+before+‘if’&aqs=chrome..69i57j69i58&sourceid=chrome&ie=UTF-8)?

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                                    jackngill
                                    wrote on last edited by
                                    #28

                                    @ Victor LOL! Nope I have been using google to try to find some form of explanation I have been trying to input code within the online compiler based on the search engines but although the search error codes are similair there examples do not work for me. I think I am going to draw a line under this endevour as coding is clearly not for me & it is far reach from exchanging one item "C:\\" for "%SystemDrive%" for another in the hope it would work. However many thanks for your patience & help I am very grateful but I have decided to quit. If you want to proceed and complete the code feel free to do so there maybe others who would benefit from it. All the best Victor.

                                    V 1 Reply Last reply
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                                    • J jackngill

                                      @ Victor LOL! Nope I have been using google to try to find some form of explanation I have been trying to input code within the online compiler based on the search engines but although the search error codes are similair there examples do not work for me. I think I am going to draw a line under this endevour as coding is clearly not for me & it is far reach from exchanging one item "C:\\" for "%SystemDrive%" for another in the hope it would work. However many thanks for your patience & help I am very grateful but I have decided to quit. If you want to proceed and complete the code feel free to do so there maybe others who would benefit from it. All the best Victor.

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                                      Victor Nijegorodov
                                      wrote on last edited by
                                      #29

                                      :)

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