Thank you very much - that did the trick. One of my testers can now run the program on Vista 64bit

Jon

I have an application that is developed using Visual Studio 2005 under Windows XP SP2. In fact there are several applications using a DLL developed under the same IDE etc. The applications load (i.e the executable runs I presume in compatibility mode) but it seems that the first call into the DLL fails the first few lines of the exception thrown are: ************** Exception Text ************** System.BadImageFormatException: is not a valid Win32 application. (Exception from HRESULT: 0x800700C1) at ScruffyDuck.Flightsim.Scenery.SceneryFile.SceneryFile..ctor(String filename, FileType fileType) at Bgl2Xml.Form1.goButton_Click(Object sender, EventArgs e) at System.Windows.Forms.Control.OnClick(EventArgs e) I do not have Vista and have no idea where to start on this. The problem has been confirmed by two users. These applications work fine under XP. I have no unsafe code as far as I know everything is managed. Any pointers would be much appreciated.

Jon

OK Thank you everyone - it is now working :)

Jon

OK apologies for not being very precise. The file I am dealing with is very large and the packed information forms a very small part of it. When extracted it has to go through another transformation. What I am trying to understand is generally how to write a function which will take a set of bits out of a larger set and return their value as an Integer. For example if I have 32 bits in a UInt32 then this is what I tried: public static UInt32 Dword (UInt32 data, int start, int end) { UInt32 result = data << (31-end+1); result = result >> (31 - end + 1 + start); return result; } I am sure the code is very poor with magic numbers and so on but if I take the example of cutting out bits 3 thru 7 inclusive then I left shift to remove bits 8 thru 31 then right shift until bit 3 is not bit 0. I have absolutely no experience of dealing with bit manipulation. Apologies again if I am not clear but it is because I really don't know what I am doing here :)

Jon

By not working I mean that the answer I get is not the correct one e.g. I am expecting 12345 as an answer and I am getting 21436 so I think I am ending up with extracting the wrong bits.

Jon

I am trying to write a function in C# (VS2005/Net 2) which will pack and upack bits into a byte, short, integer and so on. As an example I have an Int32 in a file which is packed such that bits 0 thru 10 are one value and bits 11 thru 31 another. In another I have a short where the first 3 bits represent a value and so on thru. I have been playing around using bit shifting but it is not working. I am guessing that it may be something to do with the way the types are stored - I am no expert o nthis stuff but I wonder if they are little endian so the bit sequence is turned around by pairs. Any pointers would be much appreciated

Jon

Hi Nicholas - how would I do that please? thanks Jon

Hi All I have a project which uses a treeview to the left of the main form. The tag of each treenode contains one of three different objects. Each object contains different fields of data. I am looking for a tidy way to display the appropriate controls on the right hand side of the form depending on what object is stored in the node. I can see that I could show a different form each time but I do not want an MDI like interface. My ideal would be that the controls to the right just change. Apoligies if this is trivial - I am new to vb.NET thanks in advance Jon