Also, can you check the following registry key?:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}
At that registry key, in the right window, is there, under "Name", either an UpperFilters or LowerFilters value?
If so, for each of the UpperFilters and/or LowerFilters value, what is listed under "Data"?