I have a 2 TB USB 3 external drive, but want to switch it to a eSATA external case. I have my music library on this drive & found out that the MBR on the drive is not recognized & it must be initialized. The data is not a problem, but I was wondering what is going on. It is on a Win 7 machine. I was hoping, for simplicity, that I could just put the drive in a new enclosure & it would be recognized as it was, but it doesn't seem that it works that way. I mover the drive to the old enclosure & am now backing it up to the system drive. Must all drives be initialized when they are installed on a new interface? For future reference, is there a way to make the disk portable, as in from one enclosure to another?