Well, my mother's computer runs slow or freezes now and then. Also the mouse periodically jumps around. Ignoring the mouse issue, i decided to check out the slow downs.
There were some slowdowns on startup, and after then when IE was running. IE running slow is probably what most people consider XP's sluggishness.
Uninstalled old programs, removed startup items via Autoruns, and checked out processor time in Process Explorer. The slowdowns are hardware interrupts which means drivers(, hardware settings,) or hardware.
Disabling or unplugging hardware made no difference. Shutting IE8 made all the difference. My guess is its the hard drive. Windows is notorious for thrashing the HD on startup and IE isn't too good either. Firefox had the issue to a lesser extent.
To verify this, i'd have to disable the HD. So i'm not quite sure how to continue. I could just get a new HD, but i could be wrong and just wasted $100 or whatever. I'm debating whether booting off a USB key of CD would make sense as a test.