ps2/usb mouse doesnt work/ win xp

I have a win xp sp2 system, that for about the last 6 months i had a psn mouse hooked up and it started acting flakey, then quit, hooked up a usb mouse, it works for about 3 min, and then dies, reboot and it works for another 3 min and dies,it does this w/sp1 also
what causes this and how do i fix it.???
thanks in advance.