Windows 7: New additional hard drive keeps disappearing. WTF?

So I installed a new hard drive today that I bought for additional storage, since my SSD was running low. It's a WD Blue 500GB, 7200 RPM, SATA III. --- I've seated the SATA III cable, made sure it's in SATA III slots, etc. Seated power as well, that's all good.

I've been trying to re-install a game to the hard drive, and it's a digital download. During the time a large chunk of the game is downloading (1.6 gigs), the new hard drive just... poof... disappears, or gets disabled, or something. As soon as the game's launcher tries to start installing, it freezes @ 1%. Trying to cancel it, close it, end the process, etc doesn't work, and Windows Explorer ends up crashing and restarting.

When all's back up, the hard drive is gone. The game's launcher getting stuck at 1% leads me to believe that the hard drive goes idle or something during the first chunk's download.

Some troubleshooting I've done so far:



- I've restarted the comp. Whenever the drive would disappear/freeze/close Windows Explorer/etc, restarting fixed the whole thing. And the POST sees both my SSD and the new HD when starting up.

- I'm re-installing the game right this second, with WoW running (different game) in the background, "keeping the hard drive accessed" per se... and the install is going fine. Way past the point from before.

- I've re-seated the cables.

- I've gone into my advanced power settings and set HDD Sleep time to 0 Minutes/Never. So it should never be going to sleep when I go AFK for awhile... right?

- I've made sure (via Device Manager) that my Chipset and Standard AHCI1.0 SATA Controllers drivers are up to date. (Nothing changed, it was already up to date.)


Soooo... unless re-seating things fixed this, or the fact that I'm continually accessing the drive via running another game "fixed" it temporarily (so I could install this other game lol)... What on earth is causing this? And how do I fix it?

Edit: If it matters at all, I used to have an eSATA external hard drive, and this crap would happen ALL THE TIME to it, every time I woke up the computer. I'd have to go into the Device Manager and re-search for drives before it would pop back up, or restart the computer. Insanely annoying, but... no longer an issue, I went to USB 3.0. Just dunno if this fact is relevant to you experts.