I need to find a registry subkey for mouse in safe mode, so that I can get it working and try to remove 'Spy sheriff' from my system. Is the only option to find a working 2000pro system to extract it from ? Thanks

Just been reading from the microsoft, could my problem be that, 2000 pro will not allow my PS/2 mouse to work in safe mode, and that I need a USB one instead ?

Do you use the Microsoft default ps2 mouse driver of have you installed a specialized mouse for which you installed a proprietary driver?