I have a problem with my computer, i will explain to you what happened.
Before this problem i was able to play games as; "Fifa 12", Lord of the Rings: War in the North" and Garry's Mod. When i was playing Garry's Mod, i decided to check my mail, so i pressed the Windows key on the keyboard. I forgot to turn off Garry's Mod, when i was going to play Fifa 12. I started Fifa 12 up and it stammered, i remembered that Garry's Mod was on, so i turned it off. After that Fifa 12 worked again. But the next time i started my pc, the pc itself was slower, and so were the games, i am not able to game properly anymore, please help.