Win 7 Ultimate x64 Suddenly slow, unresponsive, and hangs?

Alright, let me start. So i downloaded a game (Spec Ops The Line), and it wouldn't open. It had an error 0xc000006, but thats not what im talking about. So i searched about a fix to that error, and it said i should install DirectX/ Net Framework. So, i installed directx and suddenly my computer BSOD's. I then searched for a fix and turns out it was because outdated drivers, so i update my GPU's driver and it still had an erorr. It gave me a log of things that went wrong and i will give u guys that. So after that failed, but before that i installed NET Framework from official microsoft site. I tried the direct x in the folder where i downloaded the game, and also from official microsoft site, and the one in the folder failed and the one from microsoft worked out fine. So after i reset my computer became really slow, but before that (it was the day after then it became slow), a part of the computer's screen like half of it was blurred. So i tried the command /sfc scannow and it said i had some corrupted/missing files. Now if i try to turn on computer it will be normal for ~10 minutes, and then suddenly slow, apps wont respond, explorer freezes, etc. Thanks in advance for anyone that tries to help .

Bump.

Anyone? Please..

Just do one.restore the windows before one month back stage or the good condition stage before not near stage.do it please.may be any virus infected the system.may b not sure or downloading time any file missing or updating in hard disk but not updated properly or switch down the computer while storing the disk may can a possibility to make any prob in disk(not sure).first restore this to more earlier stage.