mystery reboots

Hello. its just me again and this does not surprise me any electrical gadget messes up for me starngely,,, OK i have some clipart(well more than some) I was going to sort them out so they would be easier to find and when I cut and paste my PC reboots at first I was doing great , then the first time it did it I thought maybe I was cutting and pasting too many at once so I was doing less and less but that does not help . the last time I selected three went to click cut and walla reboot.................................................... Help

 

System specs please.....

 

sorry, it is a Sony Vaio ,with Windows Xp Professional ,pentium 3 868 Mgh

384 mgs of Ram.

is this all you needed? sorry I forgot it....................

 

my computer reboots by it self and once in a while my screen moves then it wont let me scan for vires and i cant reboot it so i have to hard boot it i go on yahoo messanger and my friends list moves up and down ]