Sound problems in all my games

When I play games many times the sound will stop working correctly and keep repeating a little piece of music or sound effects. Eventually it stops and continues to play sound like it normally should. Also sometimes there is some static in the sound too. This used to happen often when I played music cds. This is pretty much universal for all games that I play. It doesn't happen all the time but it happens enough to be very annnoying. Annoying enough to turn off the sound once it starts happening. It can go one for several minutes like that.

I called technical support and they said it could be many things.

Here are some of my specs:
Windows XP Home Edition
Dolby Digital Certified 5.1 (6 Channel) Surround Sound Card
128MB GeForce3 Titanium-200 Video Card
ASUS A7N266-C Motherboard AGP4X / 266 MHz bus
256 MB DDR SDRAM (PC2100 266MHz) 1.5GB Max
40GB IBM 7200 RPM Ultra ATA/100 Hard Drive
CasEdge Mid-Tower Case / 300 Watt ATX Power Supply
I think my processor is one step above the 1900PR AMD Athlon XP

I'm not too sure about what I have. I think the sound card and video card are internal. They are attached to the motherboard or something?

My computer also has a little history:
Apparently a lot of dust got into my computer at one time. The fan that covered the cpu got filled with dust and the processor overheated and had to be replaced. I'm not sure when I first started noticing the sound problems because its been a while and I haven't done anything about it.

I believe I have the latest drivers for my sound card and most of my other components. The only solution I can think to try is to format the hard drive and reinstall windows. Can anyone else suggest something?