Limiting to 1 PortableApps.exe only.

Do you want code or .exe? The exe is at the link i gave, the code is there too, but the snipit is:

begin
messID := RegisterWindowMessage('UniqueAppName');
try
handle := CreateMutex(nil, true, 'UniqueKeyName' );
if GetLastError = ERROR_ALREADY_EXISTS then begin
PostMessage(HWND_BROADCAST, messID, 0, 0);
end else begin
Application.Initialize;
Application.Title := 'PortableApps Menu';
Application.CreateForm(TfrmMenu, frmMenu);
Application.CreateForm(TfrmAbout, frmAbout);
Application.CreateForm(TfrmAddApp, frmAddApp);
Application.Run;
end;
finally
if handle 0 then CloseHandle(handle);
end;