How to bring "Choose Program" screen of windows in our application

[DllImport("shell32.dll", SetLastError = true,
EntryPoint = "ShellExecuteExW",
CharSet = CharSet.Unicode)]
static extern bool ShellExecuteEx(
ref SHELLEXECUTEINFO lpExecInfo);

[StructLayout(LayoutKind.Sequential)]
internal struct SHELLEXECUTEINFO
{
internal int cbSize;
internal uint fMask;
internal IntPtr hwnd;
[MarshalAs(UnmanagedType.LPWStr)]
internal string lpVerb;
[MarshalAs(UnmanagedType.LPWStr)]
internal string lpFile;
[MarshalAs(UnmanagedType.LPWStr)]
internal string lpParameters;
[MarshalAs(UnmanagedType.LPWStr)]
internal string lpDirectory;
internal int nShow;
internal IntPtr hInstApp;
internal IntPtr lpIDList;
[MarshalAs(UnmanagedType.LPWStr)]
internal string lpClass;
internal IntPtr hkeyClass;
internal uint dwHotKey;
internal IntPtr hIcon;
internal IntPtr hProcess;
}
public const uint SW_NORMAL = 1;
const int SEE_MASK_INVOKEIDLIST = 0x00000C;
const int SEE_MASK_NOCLOSEPROCESS = 0x000040;
const int SEE_MASK_FLAG_NO_UI = 0x000400;
static void OpenAs(string file)
{
SHELLEXECUTEINFO sei = new SHELLEXECUTEINFO();
sei.cbSize = Marshal.SizeOf(sei);
sei.hwnd = IntPtr.Zero;
sei.fMask = (SEE_MASK_INVOKEIDLIST |
SEE_MASK_NOCLOSEPROCESS |
SEE_MASK_FLAG_NO_UI);

sei.lpVerb = "openas";
sei.lpFile = file;
sei.nShow = 1;
if (!ShellExecuteEx(ref sei))
throw new System.ComponentModel.Win32Exception();
}

I found the following Dll import code here: http://www.vb2themax.com Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" _ (ByVal hwnd As Long, ByVal lpOperation As String, ByVal lpFile As String, _ ByVal lpParameters As String, ByVal lpDirectory As String, _ ByVal nShowCmd As Long) As Long Sub ShowOpenWithDialog(ByVal sFileName As String) ShellExecute 0, vbNullString, "RUNDLL32.EXE", "shell32.dll,OpenAs_RunDLL " _ & sFileName, "", vbNormalFocus End Sub To get this code in your WinForms app, you have to set DllImports, (but I'm unsure of the alias part) using System.ComponentModel; [DllImport("shell32.dll")] private static extends long ShellExecute(long hwnd, string lpOperation, string lpFile, string lpParameters, string lpDirectory, long nShowCmd) {} public static void ShowOpenWithDialog(string sFileName) { ShellExecute(0, vbNullString, "RUNDLL32.EXE", "shell32.dll,OpenAs_RunDLL " + sFileName, "", don't know this one:vbNormalFocus); } This should at least get you on your way. You'll have to figure out how to get the alias yourself, unless someone else knows the answer to that.