--Solution (1)--
1- Unplug usb and restart you pc.
2- Stop A/V program and plugin usb again.
3- Do not double click to open usb directory.
4- Right click on >
USB drive >
Open in new window.
5- Single Click on > Folder < that you want to delete & press >
Shift+Delete <
YES.
--Solution (2)--
1- Go start->control panel->device manager open it
2- In view menu tick "view hidden devices"
3- Open network adapters branch.
4- You will see many adapters named Microsoft 6to4. (i had over 150 number of them).
5- Delete all.
6- Restart your pc.
7-Now Right click on >
USB drive >
Open in new window.
8-Single Click on > Folder < that you want to delete & press >
Shift+Delete or just
Delete <
YES.
--Solution (3)--
1-Right click the file or folder > Go to > properties.
2-Click the Security tab. Under Groups or user names you will probably see a string of number/special characters. If you do not see something abnormal, this will not help you. If you do, click edit, click the abnormal object (in my case it was 875-d$d) then click remove. This should then allow you to delete/edit/move the file/folder.
I hope from these 3 methods 1 can hopefully help you.
Remember you must do & follow the --Solution (1)-- before doing/following other 2 solutions.