Windows 7: USB ports stopped working

My computer crashed after doing a backup and the keyboard stopped working so I decided to remove all USBs and reinsert them then all my other USBs stopped working how do I fix this ?

And I get error 28 for all my USB drivers

Sometimes this is a BIOS issue.
Reboot your computer and hit the "Delete" button, during "post".
It should be a black screen with white alpha numerics. At the bottom of the screen it may tell you to hit a different key, like F2.
In the BIOS,check your usb setting, in case it has gone haywire.

Also update the info in the "My System Specs". More information makes it easier to trouble shoot.

ok cheers this workied to fix the usb's but i found several other issues with drives which im currently fixing

No probs. Hope you get your "other" issues sorted.

Usual easy fix for usb loss/malfunction or OS refuses to see a printer/mobile/camera etc is literally just to turn the pc off for two minutes and pull the electric plug out!

Take the battery out of a laptop so no energy gets to motherboard - this resets the usb chips and normally everything redetects including the nuisance item!