It might be too late but I think I should share this:
Insert a USB drive
1. Open Windows Explorer and right click Computer and click Manage.
2. Under Storage find Disk Management, on the right panel find your USB drive letter, right click on it, choose properties, then choose the sharing tab, check 'share this folder'.
3. Make sure that there will be only a drive letter without the USB stick name on it.
4. Click 'Permissions' - 'Add' - 'Advanced' - 'Find Now' - and at the RDN names, select NETWORK, hit OK twice then set the 'permissions for NETWORK' to 'full control'
For XP users, you might have to go back to Explorer and right click again ur USB and choose 'sharing' and share ur USB without any name except the drive letter.
If you forgot to erase the USB name, then it will only read the initial device you use to set up..
Hope it helps..