I recently had a hard drive crash and had to replace my drive and re-install QLChoirs and QLSOGold Xp NI versions (on my slave machine). I managed to re-authorize both with no issues. My question is just curiosity: It seems the authorization process is different now. Now you have to use the service center to authorize and you don't have to paste any codes anywhere. Simpler now. Originally I was under the impression that I had two authorizations total. It would seem that I just authorized a third because it never un-authorized anything (I had choirs installed on two machines). Can I use these on an unlimited number of machines?