How can detect a USB flash drive or External Hard Disk drive

To fix this problem, delete the Upper Filters registry value and the Lower Filters registry value. These values may cause access problems.
To do this, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click the UpperFilters registry value. This value is located in the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class
\{4D36E967-E325-11CE-BFC1-08002BE10318}

3. On the Edit menu, click Delete, and then click OK.
4. Locate and then click the LowerFilters registry value. This value is located in the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class \{4D36E967-E325-11CE-BFC1-08002BE10318} 5. On the Edit menu, click Delete, and then click OK.
6. Exit Registry Editor.
7. Restart the computer.