U disk mobile hard disk can not be deleted under Windows 7 solution

Since it was installed 7, it has been attracted by its gorgeous appearance and good performance, although some software is not compatible.
But when I used the mobile hard disk, the problem appeared: I can't delete it normally, the prompt is in use.
After exploring for a while, I found that one of the ways to solve
: enter my computer, re-open the mobile hard drive, and then shut down.
The second solution: close all open folders, and then delete the mobile hard disk.
The second method is tried and tested. If there are friends who have the same problems as me, please try ~
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090130 to update the following:
PS: There is also a kind Unable to delete: The anti-virus software you are using is scanning the mobile disk!