try this 1,
Click on start-->run ----> type diskmgmt.msc and click on OK. If you can see
your USB drive partition, just right click on it and select change drive letter and
paths --->then assign different letter for you usb drive.
If the problem still exists then try this 1,
1) Click on Start-->Run--->type regedt32 ----> click on OK ----> registry editor will
Note: Backup your registry by clicking on File--> Export.
2) At the left side, navigate to this location
At the right side, delete the file named UpperFilter.
3)Now Navigate to this location
4) At the right side, delete the file named LowerFilter.
Then close the registry editor and restart your PC.