whenever I start the game, It begins in a ridiculous resolution where I can only see the bottom left corner of the menu. The screen flickers really fast and changing the video settings has no affect. I dont know where to even start with this problem. I uninstalled the game and re-installed it and it worked ok for about 3-4 days. I went on a trip for 2 days and when i came back I had the same problem again only this time the re-install didnt work. I have tried to force the game to run in windowed mode and in different resolutions through steam as well as in safe mode.

iam running
windows 7 professional
amd athlon64 x2 dual core 3.2ghz
8 gb ram
ati hd 4850

Have you tryed to run Steam as administrator, just a idea may not work but you can allways try.
Right click on Steam shortcut or Steam.exe itself and select start as administrator.