No USB devices work, at all!

I do not know what happened, but it seems as if my computer does not recognize any USB device! From my iPod touch to my USB stick. It just happened recently and I have no clue what happened. I'm running on 32-bit Windows 7 Intel(R) Pentium(R) Dual CPU E2140 @ 1.60 GHz 1.60 GHz and 2 GB RAM. Please help!!!

I have also tried it using different USB ports and it comes to the same problem, "USB Device not recognized" and on device manager it shows it as an "Unknown Device".

Win key | type DEVMGMT.MSC | Enter key

Are there any Yellow question marks or red X's?

Did you recently play around in the bios?

Disconnect all usb devices.

Plug in one and only one usb stick. Does the USB stick show up when you: Win Key | Computer

Nope. All it shows is:



I only have the USB stick plugged in.

That screen shot indicates that you have a USB mass storage device connected.

Please disconnect ALL usb devices, even a USB mouse if you are using one.

Now restart your computer.

Do not plug any usb devices in.

Go to device manager again.

Does it show any yellow or red markings?


.

Thanks!! I just uninstalled the 'USB Mass Storage' and now it works perfectly!

+ Rep added.

for follow up readers
As karlsnooks says unplug all usb devices then

another way of curing this is to switch off at wall/unplug your power.supply.unit from electric (or detach elec. lead from psu) for a minute/till light goes out on motherboard - this clears/resets the usb chipset? if it's got it's knickers in a twist!