No storage media apart from opticail drives appear in Disk Management.

Hard drives appear in my computer but not usb pen drive.

Every thing appears in device manager.

I use pen drive a lot.

What can i do?

Well, that's incredibly odd. You can't even see your regular hard drives. Did you install anything or update anything recently that would have installed a filter driver (like antivirus or virtual drive software), or modify the source with nlite?

Is this a clean install?

I have the same problem, I think that it is spyware related

It's sort of a new install. 2 or 3 weeks old with no problems. I just uninstalled slysoft Virtual CloneDrive and some other stuff. Didn't help. I just tried starting windows in safe mode. Same problem.

Have these partitions been "hidden"? (If so, here we go!)

I don't think is hidden partition. I booted the PC with the old hard drive and the disk management could see all the drives. While it was working i ran 2 antivirus and Microsoft Windows Malicious Software Removal Tool. The removal tool found something and removed it but it didn't fix the problem. And now when I search for something on google the links sometimes send me to http://maybeask.info/search.php and other sites I didn't want. I think its time to reinstall windows.

I'm gonna go out on a limb here... you must have gotten a baaad thing installed that scrodd you.

Try an Upgrade Install (i.e. "Install Over Top" - you'll find instructions on that) and pray...

Same problem here! Please, if someone has found a solution help me. I have wasted the last 6 hours trying to figure out what's going on, but still can't find an answer anywhere!!! Please Help, my computer acts weird due to "drive letter conflicts" and I can't change it anywhere! Please HELP! Thank you..

I'd be interested to see how Diskpart or PartInfo views the drives.

I did it!!!!! I lost 8 hours of my precious time, but I did it!!!!!

So, what was it? drumroll............ A virus!

I checked with my Avira Antivirus, nothing. Zonealarm, nothing. Some other free antivirus programs, nothing. I've tried ANYTHING that I could from Paragon Hard Disk Manager and Norton Partition Magic, fdisk etc but it only got worse. I *almost* lost my precious files.

So what fixed it? SuperAntispyware program, which I stumbled on accidentely!

The **** virus was called Rootkit.Agent and it was hidden behind drivers/services or something like that.

Huh... figured as much. Glad you found it. And the tool to do it with