Run game application from a code

Hey guys, I'll try to be straight: Got an C# application and I have a path to Call of Duty 4 game (for example, C:\blabla\iw3mp.exe), but it's not working. I use Process.Start(path) (or @path), but everytime I got error which says almost everytime totally different exceptions... I dont have any clue what the problem could be, it's just double click on icon from my view...