Win7 can not identify the solution of u disk

        Once re-inserted after safely deleting the USB flash drive in Win7, I found that Win7 could not recognize the USB flash drive. Must be restarted to identify what is the reason? How to solve the problem? Here are a few tips to share: Steps: Right click on the computer and click on “Attributes” to select “Device Manager”. 2, in the "Device Manager", click "Universal Serial Bus Control", there will be a lot of "USB Root Hub" device list, and then right click each "USB Root Hub", select “Disable” menu, then “enable”. 3. Finally, “USB Root Hub” can be operated as above without restarting.