I have a google nexus 7, but my kids have generic tablets. I can copy movies and music files directly from my HP laptop to any of the tablets and it works fine. I bought a 64gb usb drive. When I copy the files to the usb drive and then copy them to the tablets, they won't work. Can anyone tell me why? I have tried two different usb drives. My nexus 7 only has 8gb of memory and no sd card slot. I am often out of wi-fi range and want to be able to take the movies and music with me. Could it be the size of the drive and the system it is formatted with? I know you can only format the 64gb drive with FATEX I think. Would a smaller drive work? If so, how big can I go before I have trouble. I hope someone can offer some suggestions, this is driving me nuts.