I guess it would depend upon from where you bought the software...E-Bay, probably not, SlySoft.com, yes....
What programs are you considering buying. As bilbo said slysoft is fine...from their site and so is Nero..from their site. Both offer downloads and then forward you a serial number to enter to make your downloaded version a Full version. I would be careful otherwise you may only end up with an OEM version that doesnt have ALL the features of the Full program
Good, but the AnyDVD from Slysoft is consistently ahead of the others for updating as needed for new copyright protection. If you don't mind waiting, DVDIdle usually gets their updates done.