My parent's computer is a 1.2 gHz AMD Athlon Duron (I think, it *may* be the Athlon XP, but I'm pretty sure its the Duron...). Its got 512MB SD RAM, a ATI Radeon VE Video Card, etc. It used to run pretty well, but recently, it was running real slow. Since they don't use it for much other than games, I did a reformat, reinstall of Windows XP. All Windows XP Updates have been installed. Adaware and Spybot: Search and Destroy have been run. Norton protects the computer. Here's our problem:

Computer right now is sitting somewhere around 2 - 10% CPU usage. However, if I open a program, web browser page, AIM, pretty much do anything, the CPU usages spikes to 100%, fall, and sits around 40 - 60% for about 15 - 30 seconds, then falls back to the *normal* 2 - 10% usage. Also, if you're listening to music, when you open a page/program, etc... the music begins to skip horribily for a good period of time.

Also, these problems improve at least some as the computer has been on longer.

I've also tried cleaning out dust from the heat sync and fans, thinking it might be overheating, but that didn't help.

Any ideas would be MUCH appreciated, as I'm fresh out!