Vista - Vista Won't Load/HD won't allow other HDs to load

Hi!

I'm usually able to solve any computer software/hardware related problem until this week.. I was having some issues with Vista for a month... random sketchy errors and random restarts. I used an anti-virus program and found some nasty critters. A few days later my computer randomly restarted, and once I was able to sign on and go onto my desktop, the screen would get jumbled and restart.. The next time I restarted it ran the chkdsk utility to check for drive errors and once it got to 99% it would hang forever and not continue. After that troubleshooting method, during my next restart I wasn't even able to get past the loading stages of vista (black screen after the progress bars or/and automatic restart.) I came to the conclusion that my vista boot was corrupt.. so I put in my vista cd and tried to execute a boot repair. The repairs were taking too long (I left it overnight) so I decided to shut it down. I tried to repair it again the next day, but the cd wouldn't boot past the loading green bars screen and if it did, it would show a black screen.. I'm seeing a pattern here.

I managed to install vista on another drive, by only having that other drive connected. Everything was successful. I thought perhaps I'd still be able to access the corrupt drive as a secondary or at least be able to transfer all files from it.. but that's where my current issue lies. I've tried to read up on it online, but it's very odd to me:

I can access vista from the other drive when the 'faulty' one is not connected.
I can fully access and load the vista cd when the 'faulty' drive is not connected.

which is normal..but for some reason when the 'faulty' drive is plugged in

I cannot load past the loading part of the cd...and I can't get past the loading screen of the vista from my other drive.

Weird! Having that drive connected won't allow me to access anything vista related for some reason...but disconnecting it works. And yes, my boot settings are correct. Why is this happened and what can I do to fix it.. or at least be able to access that drive's contents? I'm pretty sure the HD itself is in working order, because it does come up in bios, etc. I tried loading vista again from the faulty hd in every possible option...with no success. I tried disabling automatic restart and got a blue screen with this error:

unmountable_boot_volume

with 0xC0000185 as the second figure. Is this part of the problem?

My specs:

2 GB DDR memory
Asus Maximus Motherboard
Radeon HD 3870