In Windows XP, click on Start and then click on Run, type in "regedit" and hit enter. The registry editor will come up. Before making any modifications, please backup your registry by right clilcking on the My Computer icon at the top, and select Export.
Remove the Upperfilters and Lowerfilters values completely from the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}
Close the registry editor and restart your computer. Your drives will now show up.

