We have received a problem from some of our readers, who are not able to access their USB pen drives and other portable devices.

As according to the readers their system was successfully detecting USB devices, but may be after some kind of virus attack their system now does not detect any type of USB devices.

Let’s see how we correct this problem.

Fix:

In normal cases when you think your system is not detecting pen drives, it could be a case when your computer detects your pen drive but does not show up in my computer.

Method 1:

This could be due to no free drive letter has been assigned to your pen drive, you can refer to this post to know what to do in that case.

Still, if you don’t see your pen drive under device manager or if you see some question mark suddenly on your drive in device manager then there could be problem with your registry also,

Read method 2 given below

Method 2:

If none of your USB devices detect ,this could be due to wrong registry entries. i.e you need to delete UpperFilters and the LowerFilters registry values.

Follow the procedure listed below to correct your registry:

1. Open Start >> Run, and type "regedit" (without double quotes), and click OK.

2. Locate UpperFilters registry value. it resides in the following registry subkey:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E980-E325-11CE-BFC1-08002BE10318}

3. Click on Edit menu, and select Delete and click OK.
Note: If you receive an error when you try to delete the registry subkey, you may not have correct permissions to edit the subkey.

4. Locate LowerFilters registry value. It resides in the following registry subkey:

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

5. Click on Edit menu, and select Delete and click OK.
6. Exit Registry Editor and restart your system.

We hope this helps to fix the trouble.

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