Dimension E520 / Vista / Windows Update Problem/USB keyboard & mouse failure

Hi

Watch out, a hotfix/patch in the latest Windows Update removed my USB mouse functionality.

Plugged the USB mouse in another USB port and install failed saying unrecognised device. 

I've got the mouse working by finding the msmouse directory in the "c:\windows\system32\driverstore\filerepository" directory, and copying the .INF and .PNF files from within it to c:\windows\inf folder.

I then deleted the USB connection in System Devices and rebooted.

Upon booting eveything was fine - mouse now worked and keyboard still worked.

When I rebooted, mouse still worked, keyboard didn't.

Tried keyboard in every USB slot - nothing.  Without having a PS2 port I've hit a brick wall.

Any help would be greatly appreciated.

Although BIOS picks up keyboard fine.