Sounds like the only thing left is the case and power supply. The case has the power and reset switches on it, so a touchy reset or power switch could cause a reboot. A flaky power supply could do the same. Just some thoughts for you to consider. Peter ----------------------------------------------- The NoSpin Group [log in to unmask] p.s. Pen and paper is not affected by power failures, and does not require upgrades and service packs every few weeks ;) > -----Original Message----- > I replaced the motherboard, the graphics card in my computer > and also replaced Windows 98 with Windows XP. > > Since then my Computer reboots itself for no apparent reason > during use, including internet, games and just using > Microsoft Office. This happens on regular occasions. I have > had the system tested, but that was proved to be faultless. I > have even bought a new printer and scanner believing these > could be the cause. > > Any Ideas??? > > Steve Trinder > ENGLAND The NOSPIN Group Promotions is now offering Mandrake Linux or Red Hat Linux CD sets along with the OpenOffice CD... at a great price!!! http://freepctech.com/goodies/promotions.shtml