Start the Run Command Prompt
Type in "regedit" without the parenthesis then click ok
Go to HKEY_LOCAL_MACHINE
Then SYSTEM
Then CURRENT CONTROL SET
Then CONTROL
Then CLASS
Then find {4D36E965-E325-11CE-BFC1-08002BE10318}
The whole thing looks like this:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}
Then delete the upper and lower filters....
RESTART YOUR COMPUTER THEN THERE YA GO!
When you click on the {4D36E965-E325-11CE-BFC1-08002BE10318} 'folder' you'll see an 'Upper Filter' & a 'Lower Filter' - just click on them & then hit the delete key on your keyboard.
I think that mine popped up asking me if I was sure I wanted to do this & I chose yes. Then just restart. It should be back without any hassle. The last time I had this happen I had to go back through the same steps & sure enough one of the filters was back, so I just deleted it again & it my drive has been back ever since.