If your mouse died first and your PC also freezes up after a short time even when booting from a boot CD (Windows CD) then it sounds like hardware, possibly the motherboard if the USB port the mouse was connected to is located there.
There's a couple of quick things you can try but really no promises here as this could be a host of things.
However, as it could be a power issue, I'd try a static discharge. This means unplugging ALL cables from the PC, and then holding in the power button for about thirty seconds. The PC won't give you any indication that anything has happened, but this will discharge all static from inside the system.
Also there is a (slight) possibility of overheating, in which case you would need to open up the PC and clean out all dust, especially from the heatsink and fan of the CPU, and the cases exhaust fan.
Otherwise it's really trial and error isolating which part of the PC is at fault, but I personally would suspect the motherboard first and then after that possibly the power supply. Your next common suspect for unusual problems is the memory.