Finally after 9months of exploring, updating,installing and reinstaling usb drivers,motherboard,chipset (almost reinstalled myself) I foun a solution that works.....so people if none of this works please follow tzhis link http://ckon.wordpress.com/2011/04/08/windows-usb-proble...
This is a copy paste of text on the link :
I spent a few days trying to figure this out, and apparently all modern versions of Windows suffer from it, yet it’s barely/poorly documented anywhere:
If your usb devices are no longer recognized by Windows, no matter how many times you try to install or update the drivers, go look in c:\windows\inf\ (make sure you can see hidden and system files) and see if you cannot find:
All you have to do is restore/replace them and bingo, everything will work again, I didn’t even have to reboot.
Windows2k (2000), Windows XP, Vista and even Windows 7 suffer from this problem.
Basically my external mass storage (bulk storage) devices suddenly were not being seen when I plugged them in. Reinstalling the drivers was useless and just ended up says that windows could not find the drivers needed.
Some program uninstalls those two when you uninstall it, I am sure what, why or how but it’s yet another Windows mystery solved.
This sounds like a potential solution - but I don't have usbstor.inf in \driverstore\ or anywhere. (Searches do pull up usbstor.png and usbstor.sys.) How can I get a copy of this file? (I tried via a search, and the advertised solution, PCPareto Health, tied up my system, so I do not want to go that route again.