I have a Windows PC which I built a couple of years ago for a member of my family. Its run fine until yesterday. About a month ago it had its OS drive upgraded to an SSD by a local company, which didn't cause any obvious problems.
When I got hold of it today it was showing a Windows Boot Manager error screen:
Info: The boot selection failed because a required device is inaccessible.
Inserting a Windows 7 disk into the CD drive allowed it to boot off the CD, but a startup repair failed to indicate any problem, and it found the installed Windows 7 boot drive OK.
Since then it has gone further down hill. The PC has stopped booting off the CD drive, and now goes straight to bios without being asked to do so.
Removal of the SSD and HDD, leaving just the CD drive does not improve things. I've changed the SATA cable just in case to no avail.
Oddly, bios has no problem in detecting the CD drive, but also find a non-existent "Generic storage device", which I can't identify.
I've checked the BIOS backup battery, which reads 3.1V both out of the motherboard, and back in it.
Ominously, when I google "PC will only boot into bios", it immediately comes up with a string of problems with Asus motherboards showing this fault. I have an Asus H81M-Plus motherboard here. Are there any tests I can run to confirm I have terminal motherboard failure or should I be looking elsewhere?