I requested a demo for 3dsMax from discreet, and it gives you unrestricted use of the software for 30 days, then you need a key to keep using it. I used the full 30 days a while ago, and just recently i reinstalled the OS because i wanted to start from scratch. I decided to try 3dsMax again, but it told me it detected a previous key on the computer! I dont understand this because i formatted the HD, theres only one drive by the way. How could it know that i had a previous install of it? I dont care how to get around it, I'm going to buy the software legit, I just would like to know how it knows. Thanks!