I'm not the first one to ask this, but here are my details:
I'm running windows 7, booting off an SSD with a secondary 2TB Western Digital HDD (I bought everything about 3 months ago).
Yesterday morning when I turned on my computer, my secondary drive was missing. I looked around, it wasn't in Disk Manager or Device Manager, but the drive did show up in BIOS.
First I checked the physical connections, and moving the SATA cable to a different connector didn't change anything.
Then I booted into safe mode, poked around, and found that the HDD was vanishing as soon as Steam started running (Steam is installed to that disappearing drive). I uninstalled steam and reinstalled it, and the drive worked fine for about a day. Now it's vanishing again...Steam still seems to run without disappearing the drive, but it'll crash when Dropbox updates (my Dropbox folder is on the crashing drive, but I don't think the .exe is).
Is this a mechanical problem with the drive? Are there viruses that do this (I've scanned and found nothing)? What else do I need to do to diagnose/fix this problem?
I don't think that this is a virus at all. Rather, I think you should run a check disk. If you get the chance, backup everything from that disk somewhere else and then look into doing a fresh format. If you go to your disk manager while the disk is working, the S.M.A.R.T should tell you if the drive is healthy or damaged. Try doing a check disk, try re-formatting it (long format, not quick), listen for clicking sounds, etc... Also, if there are drivers that come with the HDD, un-install and re-install them. Worst comes to worst, your drive would be dying, but I doubt that.
If I run the WD Data Lifeguard diagnostics, or the Windows 7 check disk (with fix errors and scan for bad sectors both checked) on the corrupted partitions (at least 2 logical partitions are bad), the hard drive disappears. I have tried formatting new volumes, and formatting over corrupted volumes, and I can run the diagnostics on the new/reformatted volumes without any problems. Otherwise, disk management and WD tools say the partitions are healthy, and there are no weird sounds coming from the drives. Guess I'll try reformatting the whole thing.
Sadly, if I try to back up the data on the corrupted volumes, the drive will vanish again. Fortunately, I won't be losing any of my own work, but I do have about 200GB of apps/games/music on there that I'll have to move/download back on to this computer.
I've seen plenty of other complaints about vanishing drives like this, but they're all complaining about drives vanishing "randomly." I'm finding this problem is completely repeatable, once it shows up. Any idea what the difference would be?