Have you tried to put the USB flash in different ports or PCs? If you haven't, my suggestion is to do so, because there could be a conflict with the USB driver on your PC. If it's that so, you have manually update the driver in the Device manager.
Please, try these steps:
1. Open the Command prompt
2. Type the following command:
attrib -h -r -s /s /d X:\*.*
Then hit "Enter" and wait about for some seconds. Beware to respect the spaces between words and script. Change the letter X with that has been assigned to the USB device on your PC (that you can see it in My Computer. It can be anything, depends on each computer.)
3. Finally, browse the flash drive and delete the recycle folder and if there is another one called "Autorun" you have to delete that too.
Please, return to the topic to tell me what happened.