Well, if he's legit, perhaps it's too much FUD by others!
Alias, I try not to editorialize, boost or otherwise be a cheerleader one
way or the other. If you search Google on my name, you'll find that to be
true with regard to my posts, going back many years and that includes the
time I was in the MVP program.
I've reinstalled XP and Vista many times on different PCs without an issue
with regard to activation, even on systems where there has been some
hardware changes. That may not be the case for others, I'm aware of that
and realize my experience MAY not be typical. However, assuming a legit
copy of Vista, at worst, he may have to use the activate by phone option.
Don't read that as defense of activation. Whether or not he should have
to activate is a separate issue. My response to the OP was meant to deal
with the issue at hand and not abstract or rhetorical issues.