Ever had a battery backup that had
too many things plugged into it that the computer shuts down and gives error messages such as video not found, check video cable? Known working standalone video card, tried onboard video, tried another standalone video card, I knew worked, and tried two different video cables also, one mini, one full size. Still got same message.
First boot up, no beep (could have been bad speaker), but went into BIOS, set to boot from DVD drive, everything seemed fine. Windows was installing. Got as far as first reboot and then, got the message.
Just curious but this happened to me yesterday. I have a 650W Battery Backup APC brand, there are about 6 other things plugged into this backup, a LED light, a HP IPS monitor, a Dell laptop, a canon printer, and the desktop and a powered USB hub.