every now and then my computer, which i just recently built with all brand new supplys (asus k8n mobo, amd athlon 64 3000+, western digital 80gb 7200 hard drive, aspire x-gear case with stock 350 watt ps). i am running 4 80mm fans a hard drive cooler fan two cdrw drives, and a floppy. my problem is that every now and then my computer just reboots (restarts) like i hit the reset button with no warning or anything, no shut down screen, nothing. what could be the cause of this? any help would be apreciated. it almost always sounds like, to me anyway, that the hard drive just stops, kinda like it winds down, clicks, and thats it. but it is also brand new, and i had this problem for a while, and this is the second hard drive ive tried with the same problem. please help.....