OH HOLY CRAP (Computer Stuff)
So, I was using a trial of O&O disk defrag earlier while playing around on my computer, and everything abruptly freezes, so I reset the computer.
When it boots back up, my second hard drive is gone. Even in BIOS. I freaked out a bit, and while searching for related problems on the internet (after doing the obvious: turning my PC off and on a couple of times, and a system restore), someone had a similar error using the same defrag software (O&O), but there wasn't a known fix.
Eventually, I hit step 3 of any electronics troubleshooting (unplug it then plug it back in), opened up my PC, and voila, it worked again.
Long story short:
BEWARE O&O DISK DEFRAG.
When it boots back up, my second hard drive is gone. Even in BIOS. I freaked out a bit, and while searching for related problems on the internet (after doing the obvious: turning my PC off and on a couple of times, and a system restore), someone had a similar error using the same defrag software (O&O), but there wasn't a known fix.
Eventually, I hit step 3 of any electronics troubleshooting (unplug it then plug it back in), opened up my PC, and voila, it worked again.
Long story short:
BEWARE O&O DISK DEFRAG.