Last wednesday (6 days ago) I reformatted my c: drive and did a clean install of XP pro (sp2 slipstreamed). Since then I haven't had a chance to sort out the software side of things and have been using my wife's laptop. There is nothing on the xp system at all, no network cables are connected and all external devices are unplugged. For some reason last night at about 12.40 I heard that irritating windows startup jingle. When I had a look at the pc it had switched itself on.