My computer has Alzheimer's!

[Himegoto]

This problem is especially evident while playing games. At random intervals my computer seems to forget what its doing, stopping almost all processing for three seconds to several minutes, after which it continues on like nothing happened. While the computer seems to be frozen I am still able to move the mouse cursor around, however all other processing ,including background, stops. I've tested the RAM & checked the running temperatures. I'm thinking maybe I need a new video card with more RAM but am hoping that its something cheaper to fix.

OS: Windows Vista
Processor: AMD Athlon™ 64 X2 dual-core processor 4400+ 64-bit
Video : NVIDIA® GeForce® 6150SE 128MB
RAM: 1024MB DDR2

 

[mailpup]

Could you have a process working in the background like an anti-virus automatically updating itself?