For some reason, the computer I built a couple of years back has taken to doing an odd reboot loop. It had been working fine, but now when I turn it on it POSTs as normal, starts to load Windows (7 Home Premium 64bit), but when it gets to the point where it would normally show the login screen it jumps to chkdsk. It goes through the tests, often saying it's fixing things, then restarts. After restarting, it does the same thing again, ad nauseum. When it starts chkdsk is says 'press any key to skip/cancel', but pressing a key on the keyboard does nothing. I've tried using the install disc to do a repair, but it doesn't make any difference. I've run the samsung HDD test tools from the ultimate boot cd which have come back with no errors. I've also run memtest from a flash drive and left it running for over 100 hours. In that whole time it did give two errors, but I don't think that's responsible for causing the constant reboot loop. The worst I ever used to get was an occasional BSOD/reboot. Any ideas? It's driving me spare. I'd rather not have to, but the only option after this is to boot a linux livecd and backup anything super-essential to an external HDD. Thanks in advance.