Great! Thanks. In case anyone else is interested, here's the code I came up with. private const uint SW_SHOW = 5; private const uint SEE_MASK_INVOKEIDLIST = 0xC; private struct SHELLEXECUTEINFO { public int cbSize; public uint fMask; public IntPtr hwnd; public string lpVerb; public string lpFile; public string lpParameters; public string lpDirectory; public uint nShow; public uint hInstApp; //optional fields public string lpIDList; public string lpClass; public IntPtr hkeyClass; public IntPtr dwHotKey; public IntPtr hIcon; public IntPtr hProcess; } [DllImport("shell32.dll")] private static extern long ShellExecuteEx(ref SHELLEXECUTEINFO s); public static void DisplayFileProperties(string path) { SHELLEXECUTEINFO shInfo = new SHELLEXECUTEINFO(); shInfo.lpFile = path; shInfo.nShow = SW_SHOW; shInfo.fMask = SEE_MASK_INVOKEIDLIST; shInfo.lpVerb = "properties"; shInfo.cbSize = Marshal.SizeOf(shInfo); ShellExecuteEx(ref shInfo); }

There are no Win32 or Message functions you can use to speed this up. The problem is that you're using the worst control you can to do this. The RichTextBox does not lend itself well to syntax highlighting. Unfortunately, it's also the easiest to use without writing your own TextBox class to support this. You may want to do some research by chekcing out these[^] articles to see if you can pick up a faster technique. RageInTheMachine9532 "...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome