How much memory and what type do you have? And How big is your pagefile (virtual memory)?

It could be that soulseek is the problem:
http://www.google.com/search?hl=en&l...mp&btnG=Search

Could be corrupted ram, due to the age of the machine. Have you defragged lately? When was the last time you did a complete reinstall of your OS? I recommend once every 6-12 months. Backing up all existing and pertinent data beforehand.