you can copy your internal drive to another drive using a computer, maybe to get a bigger hard drive, or as a backup, but the recordings can be only viewed in the receiver that made those recordings, they are encrypted/married to the receiver. (you can't play them on a computer).
You'll need a computer with two SATA ports and Linux, the receivers use a filesystem called XFS, there are some posts on the "other" DBS forum about this.
I have upgraded my HR22s from 500GB to 1T drives, and my HR44 from 1T to a 2T drive, I even backed up my HR24 to an external USB drive.