Is my HDD Screwed? (Other Issues too)

Okay so ran into a problem here. 

Bought a new SSD to add to an older system with a 5200 RPM and Windows 7. 

Installed the new SSD and installed Windows 8.1 to it. After the restart it showed the Windows logo and the spinning circle and never went past it. 

Eventually I unplugged both drives and reinstalled Windows 8.1. It boots and is working fine but I want to continue to use the old 1TB drive for storage. If I plug it in while Windows is booted it doesn't show up. If I turn the PC off and plug it in the Windows 8 logo displays and the circle spins but never boots. If I unplug the HDD it starts up fine.

Any ideas?

UPDATE

Unplugged and plugged the HDD in with Windows 8 on the SSD booted. The drive shows up but so does another partition called SYSTEM (I:)

It is 99.9MB. Opening it just reveals a folder called Temp and it has some temp files it it that are from 2011. 

OKay guys. Completely at a loss here. 

So I started this machine up today. No problems all was well. I used it for a bit then started up Skyrim. It froze during a loading screen and I did a hard reset. Following that the computer was taking ages to boot. Not the 10 seconds it took previously. 

Finally seemed to be okay after a few restarts. Just decided to try again one last time. Computer is doing the same thing. It refuses to boot with both the SSD and old HDD installed. If I unplug the HDD it boots fine. Otherwise, it just sits at the Window 8 logo with the spinning circle. 

Any attempt to plug in the HDD when the computer is booted causes the machine to act strangely. Explorer freezes but other programs are unaffected. I can still use them but I can't open anything else.

Task manager recognizes the drive and I can monitor it under "Performance." The Active Time is 100% but Average Response time, as well as read and write speeds are 0. Every few seconds the reads and writes will move and active time will drop but then it is right back up to 100% and all 0s. 

Any ideas?

Ran the onboard diagnostics. Throwing off a BIOHD-8 SMART error on the HDD. Drive fucked?