windows 7 upgrade questions

[davew]

i'm a bit out of touch with all this ,my son would like to get a copy of windows 7 professional he can get it fairly cheap as he is at school it's the upgrade version.
he is currently running a retail version of vista ,if he gets the upgrade version does this mean that the vista that is currently on his machine can't be used on another pc.
what happens if he upgrades his pc will he need to buy another copy of windows 7 .

 

[Kaeo]

Oem or retail? Oem copies are generally motherboard specific, so you'd only be able to use it on that pc anyway. You can generally do whatever you want with retail copies.