Win 7 can no longer recognize the U disk problem

Once re-inserted after Win7 safely uninstalled U disk, I found that Win 7 can no longer recognize this U disk. Then you have to restart your computer to recognize it again. What is the reason? Let's solve this problem:
First click on the Windows 7 desktop mouse and click on “Computer”, and then select “" Properties”. Click on the “Device Manager” in the top left corner. In the pop-up “Device Manager” window, click on “General Serial Bus Control” and there will be a lot of “USB Root Hub” devices list. , then right-click each "USB Root Hub", select “Disable” menu, then “Enable”.
Every "when the USB Root Hub" is operated like this, Windows 7 can recognize the USB flash drive again without restarting.