all my os's are OEM.
only ones i actually own are 98SE and NT4 Server lol.
if they dont activate then meh, i just bring ms up
with OEM versions ms dont reeally seem to care so long as you explain that the HW failed and the system builder replaced it.
I always have bloody trouble activating office though. Student 2003 can be installed on up to 3 computers under the EULA, and i then sent away for an MS special offer to get ms access for like $5 essentially turning it into pro. But access activates seperately, and so ms say oh no its installed on more than one, at which point i tell them that the damn disk has no eula on it but says "step-up software, use only with a valid licence for office 2003 student" , imlying it was licenced under the same terms.
Took me ages to get office activated so i hateb reinstalling it.