The electrical current that is supposed to flow between the PC and a serial mouse is small, and even smaller for a PS/2-type mouse. So the most likely source of the shock is "static electricity" which can build up in your body as you walk around. [It's not usually a lot, but it's worse when the humidity is low, and it may be made worse by combinations such as rubber shoe soles on synthetic carpets.] There are various ways you can dissipate any accumulated static before you touch the mouse. The three most common: (1) Touch the case, or another *grounded* part of the PC first. [BUT see below....] (2) Install an "anti-static mat" under your chair. (3) Install an anti-static wrist strap, attached to a ground, and put it on before touching the computer. NOTE: I had a PC that would sometimes reboot when I touched it, about 20 years ago. None of the measures above seemed to help. What finally fixed the probem? It turned out that the PC wasn't plugged directly into a three-prong electical socket, but reached the wall via a two-prong extension cord. Once the third prong was properly connected to ground, the problem disappeared. David Gillett A+, MCSE, CCNA, unemployed On 2 Jun 2001, at 20:21, Al-Torath Int. Trading Est. wrote: > Hellow Friends > I am facing a strange problem. During working often I have to > leave my seat while my PC running, when I come back and touch > mouse suddenly I feel electric shock and system is also > automatically rebooted with that shock. I face this problem more > than one time every day. I am unable to understand that from > where comes this current to shock me and why/How PC is rebooted at > same time without touching any part of it ? Is there any solution > ? > Thanks in advance > > Murtaza Malik PCBUILD maintains hundreds of useful files for download visit our download web page at: http://freepctech.com/downloads.shtml