Copying files from and external usb drive to an internal usb drive

I wan to copy files from an external Usb drive to and internal usb drive. The tablet formatted the internal and can only be used in this tablet. I have purchased cable to run the ext keyboard and an external usb drive at the same time. When I first started, I wanted to just simply put the usb drive in another computer, copy the files, and then remount it in the tablet. Not so, once the Envizen formats it, the other computer will not recognize it, and if formatted in the computer the Envizen will not recognize it. So the virtual keyboard offers none of the normal commands and the external ke has no cursor key.

Stuk, may have to return it!!!

Thanks