Dear TrueNintendo, While the vast majority of USB keys is compatible with the Sagemcom set-top box range it can occasionally come to compatibility issues between two USB devices (your box and your USB key) from different manufacturers. Keys that are not larger than 4GB in size and also formatted to FAT32 do usually work with our set-top box range. For more information on how to prepare your USB key you can visit our Online Support Community via our website, contact us.