"No valid boot device" wierd problem

[lavagninogm]

Just recently my computer (ASUS A8n-SLI Deluxe MOBO with an athlon 64 2.0 ghz processer and a Nvidia 312MB 6800 with 1024mb ram) started giving me a message on startup saying "No valid boot devices" but the kicker is that on that same screen it registers my 2 hard drives.

I thought that maybe i just needed to repair windows but when i try to it sayd that there are no disks to install/ fix.

On top of this problem my computer somtimes on startup wll turn off about 2-5 seconds after i press the on button.

I know a decent amount about computers and built this system myself but i cant seem to troubleshoot it, I replaced the master HD with one from another computer and still nothing, any advice would be very stress relieving :)

[Paleo Pete]

On top of this problem my computer somtimes on startup wll turn off about 2-5 seconds after i press the on button.

First get that wrinkle ironed out. Heat and power supply are the two most likely reasons, shutting down in a few seconds makes me lean more toward power supply, but the hard drive problem is added into the mix so disconnect it first and try the computer with a bootable CD like Knoppix or an Emergency boot CD. If it still shuts down, try a different power supply. (it could also be related to a bad cable, I've seen stranger things happen)

If it works, the power supply should be ok. Then hook up the hard drives, one at a time and make sure both are jumpered to Cable Select. Swap the hard drive data cable to eliminate a bad cable.

Then once you can get it to boot and stay running, check the hard drives with the manufacturers' diagnostic software, usually available on their website.

The "No boot device" error message could be because the drives are not jumpered or set right. Are they IDE or SATA? If IDE, they usually work best jumpered to Cable Select. If both are jumpered Slave, the computer can't recognize either one as a bootable device. In some cases they will have to be Master and Slave, but usually it's Cable Select for both. The jumper configuration should be printed on a label on the drive.

[lavagninogm]

where would i be able to get one of these boot CDs? the HDs are SATA, ill be able to test out the cables and all that good stuff tomorrow, thanks alot for the advice :)

[Paul Komski]

replaced the master HD with one from another computer and still nothing
Sata's always have a dedicated channel and cable and no slave relationships. Do in particular check the BIOS setup to check that the drive is detected there and correctly placed in the boot order.

Some utility boot CDs (http://paulski.com/zpages.php?id=1813).

[Sylvander]

How to make a free EBCD bootable CD
http://www.pcguide.com/vb/showthread.php?t=41485