Last night my computer just froze, I then restarted it and it got back to windows (windows 8.1) but wouldn't load any icons and the cursor was constantly showing the circle loading thing. Tried resetting a few times, sometimes it would say no boot device and sometimes it would goto windows but not load anything.

I have an OCZ Vertex 2 (prob 5 years old?) as boot drive and HDD for storage. In the BIOS it's not even showing the SSD at all so I think it's dead... but how come it will sometimes boot into windows?? Is it completely dead or can I revive it?

I've had to put Ubuntu onto a USB at work to put on the PC when I get home for now and will run it off the HDD if the SSD is dead.