I recently installed a fresh copy of Windows 8 Pro (full version, not an upgrade) onto my desktop (self-built). One day it restarted for no reason (was not a Windows Update restart) and when it rebooted, it came up with an error that it could not find the system disk. I believe that it was a power hiccup, I've since gotten the system to identify the disk again and have had no errors with it (ran chkdsk, and have been able to browse with an Ubuntu live USB). Now when I try to boot, all it gives me is an orange screen with thin white stripes, and a single blinking "underscore" cursor at the top. I've tried the full gamut of repair & restore options (bcdedit, bootrec, "Refresh Your PC", etc) with absolutely no luck. I am at a total loss, and honestly can't find anything on the web describing the same issue.
If it helps, it is UEFI BIOS (which is a contradictory term I suppose) but the disk is not EFI/GPT. It's a standard hard drive, with one NTFS partition (that does not fill up the whole drive). I did have the primary color of Windows 8 (start screen, etc) as the same shade of orange that is now showing, but I don't see where that would matter.
This is the screen I get. The color variation is an optical illusion; it's actually all the same color as at the top.
Best Answer
This really looks like hardware failure to me. I've seen similar things when a video card fails or begins to fail. Try using a different video card to see if the issue persists. Make sure your power supply is rated to handle your video card and everything else in your system.
If it's a power hiccup it's possible your system may have been damaged because of it.
If it persists - did you recently update the UEFI BIOS? If so, perhaps it's not properly initializing the chipset or video card, or there is some issue with ACPI. See if there's another update or if you can revert to an earlier version (not likely). Bad RAM or other hardware like a PCI-E/PCI card could also be a culprit.