So I just reinstalled Windows 7 on my dad's PC. The thing is i accidently installed Win 7 Ultimate (x64). The key (legit key) I have is for Win 7 Professional (x64).
What are my options. I do have the ISO for Win 7 professional also. Is it just cleaner and safer to reinstall Win 7 professional? how bad is it on the harddrive? the harddrive is fairly new.