I pressed enter to soon. Will Photoshop 7.0 upgrade version work and be legal to use on an academic version of Photoshop 4.0 that by brother bought? Would I then be able to use the Upgrade of Photoshop 7.0 for commercial purposes?
#1
As long as your brother bought it for you and is not running 4 himself, yes you may get 7 upgrade.
#2
Physically, it will work. As far as legally, the answer is, it depends. If your brother bought the academic version because he was a student or teacher, AFAIK, he can't transfer that license to someone who wasn't a student or teacher. If I'm correct, and as already pointed out, you should check with Adobe, you wouldn't have a legal copy.
Bob
#3