 luaynevan636, The premium version of the app is tied to a particular machine via a machine identifier key. So, you cannot use one license on multiple machines. You can however back up multiple machines to a single location if each has DBaR on it.  I.e. One ext HDD (Rescue Disk) can store full system backups from several machines.Premium version of course.
purchased back & recovery for laptop. can I use on desktop as well?
back & recovery