i like playing games, on may 22 my pc started to play games realy choppy (i play tf2, portal, spore)
my specs are:
cpu=Pentium(R) Dual-Core CPU E5200 @ 2.50GHz
cpu speed=2.50 GHz Performance Rated at: 3.75 GHz
Video Card=GeForce 8400 GS
disk space=149.6 GB
I wonder.. is your pc a desktop or laptop? Not sure if it would matter...
But like everyone else said. Clean your computer. Perhaps you have some software that got installed and is running in the background? You could try upgrading memory but if it worked before, something has changed since then. Did you move your computer? Perhaps you're not getting enough air flow to cool your parts better.