Win 7 system can not recognize the U disk solution

            Once I re-insert the U disk in Win7, I found that Win 7 could no longer recognize the U disk. Then you have to restart your computer to recognize it again. What is the reason? Here's how to solve this problem:
First click on the Windows 7 desktop mouse and click on “Computer”, 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”.
Each of the "USB Root Hub" operations is done this way, Windows 7 can recognize the U disk again without restarting.