Windows Vista Activation

[Teny]

i got a windows serial key from the side of my brothers computer and right now hes using XP, so now i got a vista key, but it says its OEM. his computer didnt come with a install disc, so downloaded a copy of vista SP1 on a site, cant tell you guys because of the rules. I installed it, and used the OEM key, but it said "Windows Vista Home Basic product key you typed is invalid for activation." it worked when i was installin windows, but when i got on, it showed another Key that has the word OEM in it. tryed entering the key again, but the message above shows up.
the only options that shows up is Activate by phone, and Buy another Product Key.
any help on whats wrong or what to do?
i dont want to call either....
thanks in advance

 

[cwharms]

an OEM key is only going to work on the computer it was initially installed on, ie; same cpu/mobo

 

[worshipme]

Yes and if you do a big upgrade you will have to call Microsoft and let them know that the copy is still only being used on one PC and they'll give you another licence key.