Installed Win7 pro instead of Win7 Ultimate Can I use the anytime update to activate?

[Sprtfan]

I built a computer for a friend that is a student. He didn't have the OS yet but told me he could get Win7 Pro from his school. I put it together and installed Win7 Pro on it since I had a copy and told him he would just need to activate it once he got his product key. It turns out that he could get Win7 Ultimate not Win7 Pro. Can he just use the anytime update option to activate? Will it be a problem if the Win7 Pro is not activated (I read some where that you can upgrade an unactivated install)?
I have not used my Win7 Pro install yet, if it needs to be activated to use the anytime update, I can activate it with my product key so he could upgrade. Would this cause me any problems when I go to install my Win7 Pro though? (Would my Win7 Pro product key still be usable or would it be tied to the Win7 Ultimate upgrade and no longer work?)

Thanks

 

[GreenMonkey]

I did this, sort of. I used the product key from my Pro for the Anytime upgrade program from Home. I installed Home before w7 launch date and ended up with Pro retail keys instead. It acted a little strange though (I remember I had some problems with it)...but booted up as Pro and worked OK from there.

http://www.sevenforums.com/general-discussion/32620-using-upgrade-key-anytime-upgrade.html

http://social.answers.microsoft.com...l/thread/2c2f3e4f-927d-47d5-a703-263b415d634e

I'm pretty sure it wouldn't kill your own key, but I can't swear to it.

 

[Sprtfan]

Thanks for the information and links. It looks like it should work with out entering my Pro key first. I'll have him give it a shot.