I'm not sure what's happening but I have a feeling it's either Win 7 or a hard drive about to fail. Starting this morning I had a lock up of my PC which I then had to turn off the power to the PC and then restart it. I started getting the "reboot and select proper boot device" prompt which with past computers has meant a hard drive was dying. I'll power it off again and it'll boot normally into Win 7. I will leave my PC on and then after 20+ minutes, it will reset and the prompt will come up again. Now my main concern is that I don't know which HD could be failing. I have a 120 GB SSD as well as 1 TB HD.
My specs as follow: Win 7 64 bit Pro i3 760 2.8 Ghz 120gb OCZ SSD 1 GB WD HD ATI 5870 1 GB
More aboutrandom shut down
Run a hard drive test on the WD in dos...with ONTRACK or HIRENS...
Since it tells you to select boot device, it is the drive with windows on it.
It may be worth a swapping out of the power cables(just use another plug) and data cables. I have seen bad sata cables do some funky stuff.
And yeah, all that stuff above is great too(wdc tools and what psu?).
Agreed with "nukemaster" If it is faulty drive then it must be the primary drive with OS. Also changing drive data cable is a good idea. You can also check connecting other power cable.
Disconnect the other drives and CD ROMs and then turn ON and check if it still reboots or not. (Sometimes power supplies become weak and couldn't provide power to all devices)
might Google your motherboard looking to see if the SATA controller has had problems. I had a biostar they built with a batch of bad SATA controllers that would start to fail after a year or two. same intermittent problems.
So the SSD was faulty. Had some diagnostics run on it by an IT friend and something with putting my computer to sleep instead of shutting it down completely every night caused the drive to simply run out. I ended up buying an intel 320 series 80gb SSD to replace it.