I have two external Seagate drives. The first is Flash Drive (FreeAgent Drive) and the second is (GoFlex drive) (USB 3.0).
I wanted to copy from one to the other while both were attached. They can't work together for some reasons. The one which was plugged first is shown (for example like: "J" drive) and the second is not shown at all but still visible from the Safely Remove and Eject MEdia tray, so I can eject them..
The system I'm running is Windows 7 64 bit and is up to date and I believe it's free from viruses according to Norton :D
They both are seen in the tray (Safely Remove and Eject Media).
They both work 100% seperately.