Windows 7 - Hard Disk dropping

Like a month ago I found my second hard disk was gone (Windows or BIOS couldn't see it) and suddenly it came back like 2 days after (this time I could see it under my computer, but couldn't access it). After a week it just suddenly started working again.

Now it worked just perfect until today. I still see it, but can't access some folders or run programs.

What should I do with this?

Check the hard drive with the manufacturer's diagnostic tools.
Hard Drive Diagnostics Tools and Utilities (Storage) - TACKtech Corp.
HD Diagnostic

Humh.. what of those Western Digital tools should I download ?

The first link should do. Gives you both the windows and DOS version.

You'll also want to start copying data from the drive:

Copy & Paste - in Windows Recovery Console

Or, failing the above method, a Linux Live CD may allow you to see and copy files from the drive.

James

I downloaded some app from here
WD Support / Downloads / SATA & SAS / WD VelociRaptor
And all it told was "There were errors that we can't repair, contact support. (error 08)"

Now Windows threw a message "Want to check for bad sectors?"
I did press "yes" and it asked to force dismount drive.. So it did and scanned it (I think) but now the drive is dismounted..

So now I even can't see my second Hard Drive.. Any tips how to get it back? Last time it just became normal after a week.

Click Start orb type Disk Management, click on Create and format hard disc partitions. A new window will open, can you expand this window and then copy and paste it here using the snipping tool.

Here..

Not looking good you could try the connections to the device to ensure they are still sitting properly. If it is also not showing in the BIOS and Device manager I would say that it is an ex HDD.

Well it doesn't show in BIOS (like it didnt last time) but last time it just suddenly reappeared? And cables are fine.