Well, if you haven't deleted the ISO yet, then you can go in and change a file (I think it's ei.cfg) to say Ultimate instead of Professional, and then reinstall. The beta keys work on Ultimate. You could also download SoLoR's ALLSKU version and install Ultimate. There are no ways to get the keys to work for the Pro version.
i just gave a friend a copy. ill have to let them know that the ms keys only work on the ultimate version. i have a program that can change cd keys... so if someone knows where to get working keys for the other versions that would be great!
Yes, the beta keys are only for Ultimate, like a previous poster said: go into the iso and delete ei.cfg to do this, extract the ISO to your hard drive then open the folder where you extracted it to and go to the "sources" folder and find and delete the ei.cfg file. Now open setup.exe (back in the main extraction folder), you can now install whatever version of Windows 7 you want (in this case, it's Ultimate)