1. Click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE/System/CurrentControlSet/Control/Class/{4d36e965-e325-11ce-bfc1-08002be10318}
4. On the File menu, click Export.
5. In the File name box, type savedkey, and then click Save.
6. Click the REG_MULTI_SZ data type UpperFilters, and then click Delete on the Edit menu. When you are prompted to confirm the deletion, click Yes.
Note If this data type is missing, go to Method 2.
7. Click the REG_MULTI_SZ data type LowerFilters, and then click Delete on the Edit menu. When you are prompted to confirm the deletion, click Yes.
8. Quit Registry Editor, and then restart the computer