Can you give us a little bit more detail about what's happening? Do you see any error messages when you start the game, or does it simply not open up?
Like it was previously suggested, it might be useful to reinstall the game and try to run it without your mods enabled. If you don't have your download link, either email firstname.lastname@example.org or email@example.com with your purchase details (name and email address), so we can resend you that information.
Hope to hear from you soon!