Slow performance with all video games whether old or new

[godfather@18]

hi dis is godfather@18.
I have a computer and i love playing video games in it. But dis is happening for few weeks. when i install and play games whether old or new, the game start performing well as it used to, but atfter 10 or 15 minute the games slows down. it slows down like it will take my whole life to complete it. when i had purchased my computer it did not used to give this problem. dis is happening for past few weeks dis year.
I have installed and tried softwares like tuneup utilities 2011 and uniblue speed up my pc 2011. But the problem persists. Check out my pc configuration:
1: intel dual core 2 ghz
2: xfx nforce 630i/geforce 7100 motherboard
3: 2 gb of ram
4: nvidia geforce 8400 GS 512 mb

Though it seems that my pc configuration is like scrap, let me tell u dat dont under estimate it. it is still capable of running latest games.

URGENT SOLUTIONS NEEDED!! PLEASE HELP!!

 

[lordpelvis]

I would say that you have a program that has a memory leak. Run a game, and then press ctrl, alt, and del buttons at the same time. Open task manager, and see if there is a program that is using up your memory, or cpu.

 

[venjhammet]

How old is your Pc? Have you check the temp of your cpu and gpu lately while playing or have it clean, free from dust? Could be overheating.

 

[hang-the-9]

Don't mess with any of those programs you installed. Re-install Windows, and upgrade your video card, the 8400 is junk for games. You can get a $40 video card that will increase your video performance by several times over.