Windows 7 Can't access my D drive Partition

[Mastaan]

I had 2 partitions on the same hard drive, and I did a clean install of Windows 7 Professional, but for some reason I can't access my D drive, I belive it has something to do with the Security Settings. I had important file in it. Is there a way I can access my files? I tried running diskmgmt.msc, but nothing shows up.

Thank you

 

[beware]

I had something similar.
One of my drives didn't turn up after restart.
In discmanagement I noticed this drive didn't have a character (e.g. D or E or F) assigned to it.
After I assigned a character to it, it showed up in my computer.

 

[Asuterisuku]

I'm having a similar issue myself. I can see the partition in diskmgmt, but it won't let me do anything with it. When I right click on the partition - Which is half of my hard disk! - it only brings up the "help" option, and the drive mount buttons are all gone from the bar along the top. And it doesn't even appear when I try to run it in command line.