My Xbox360 doesn't detect any USB key, what can be done?
Check the type of formatting your USB drive: FAT32 or NTFS?
NTFS does not appear to be supported by the Xbox 360. While FAT32 it is perfectly supported by the console and is immediately recognized, allowing you to play your media files (. mp3,. avi,. mp4 and . mkv).
But there's a problem!
The main difference between these two types of formatting is the size limitation: you can not move large files on a FAT32!
Thanks to Cous for this tip.