Normally, if a Windows Update driver installation fails, the original driver remains installed and continues to function.
If the Windows Update driver installation fails after the new driver files have been copied, and the original driver files have been removed, but before the registry information can be completely updated, the device may stop working.
To resolve this problem:
1. Start / Run / Devmgmt.msc / OK.
2. Right-click the device whose driver you attempted to update and press Properties.
3. Select the Driver tab.
4. Press Roll Back Driver.