USB causes total shutdown of the computer

well, I had this problem since I have the computer, but now it is really anyoning, when I plug an USB device that must creat an unit, such as a camera, or my pendrive, windows just reboot, know It is not a hardware problem, since I used the debian live cd and there was no problem, and I have tried all posible solution, my computer is a pentium 4, with a MSI PT8 NEO-V motherboard, whit 256 mb of ram, and it currently has 2 printers (both conected to the SUB ports in the back) an one pair of speakers that thake the power from the USB ports (also in the back)
I have tried to unplug those elements, but the result was the same... any Ideas!?
I am running win XP whit service pack 2