You are looking for the Windows Shell32.dll "ShellExecute" function.  Except
for the actual reference to the Windows API, which I don't know how to
convert from VB to C#, here is the code to open an arbitrary file.
Hopefully someone else can convert the API reference to C# for you.

// The Declare statement below needs to be converted to C#.  The converstion
will start
//  [DLLImport "SHEL32.DLL" ...

// Private Declare Function ShellExecute Lib "shell32.dll" Alias
"ShellExecuteA" _
//    (ByVal hwnd As IntPtr, _
//     ByVal lpOperation As String, _
//     ByVal lpFile As String, _
//     ByVal lpParameters As String, _
//     ByVal lpDirectory As String, _
//     ByVal nShowCmd As Int32) As Int32

enum WindowShowConstants {
    SHOW_FULLSCREEN = 3,
    SHOW_ICONWINDOW = 2,
    SHOW_OPENNOACTIVATE = 4,
    SHOW_OPENWINDOW = 1

System.Diagnostics.ProcessStartInfo psi = new
System.Diagnostics.ProcessStartInfo("FileName");
psi.UseShellExecute = true;
psi.ErrorDialog = true;
System.Diagnostics.Process.Start(psi);
--
Tom Porterfield

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