Splinter Cell Conviction doesn't start

I just bought a new PC with Windows 7, and as my first game I installed Convicton, but it didn't start. I got error messages stating that some .dll files were missing. ı searched in some forums and someone said that I should download and install this. So I did. After that, when I tried to start the game, I didn't get any errors anymore, but I still can't start the game. It looks like starting, I get a short black screen, the one you see before starting some games, than nothing happens. What's the problem?

Game's legit, my system configurations are stated on my profile.

Have you tried patching the game? Running as admin?

No, I didn't try that.