Win 7 Suddenly Stopped showing USB Drives

Hi all, I recently got Windows 7 64 bit.
the day i got the machine home and running, i connected my USB harddisk and installed some stuff i had backed up from it.

But suddently i dont see the USB drives when i connect them, i have 2 and none of them is detected, or will they are detected and the "Safelly Remove Hardware and Eject Media" icon comes up in my right lower corner as it should, and when i click it my devices is shown by their propper names and i can safely remove them aswell. but they are not shown under "my computer" and my anti virus dosnt scan them aswell.

Tho if i plug in my USB flash pin from my key ring it finds it, anti virus scans it and it shows up just as it should.

Can anyone help me solve this as im really confused by now.

Thanks, and thanks for the reply
it did not work, BUT i think you are right, i saw that the devices show up under the "Devices and Printers" and i checked driver date, it says 2006... i tryed to uninstall the driver but it seems just to reinstall the same driver as i connect my device again.

Thanks a lot again m8... I ended up re-installing windows before i saw your latest comment, so not everything is working as it should.

I cant give you rep again it says, i need to spend some on others, or i would have given you more..