Windows 8.1 BSOD on startup: 'INACCESSIBLE_BOOT_DEVICE'

I'm sorry to make another post within this area of the forum on the same problem, however I thought it would have been easier to start a new topic seeing that new developments have occurred and that it's been ages since I posted in the my last thread here. And now to the topic.

My desktop's been unable to boot to Windows 8.1 recently, as it's been getting a BSOD saying 'INACCESSIBLE_BOOT_DEVICE'. This started happening after a few of the GPU crashes (black screen and loud fan noise) with the XFX 3GB Radeon 7950 I've got.

The desktop is still under warranty, so should I send it back, or is there something I can do to help this?

send it back

The first step is to run hardware diagnostics to ensure that the hard drive hasn't failed.
Start with these: Initial Hardware Diagnostics

Or, you can have the warranty center run the tests - as they'll be the one's to replace the hard drive if it's bad.
Depending on the center they may either reinstall Windows - or may ask you to provide recovery media to restore Windows.