I asked Microsoft that question a few months ago and was told that there is
no mechanism for doing that (Adobe has an online way of deactivating--which
works about 25% of the time, in my experience--but I'm not aware of anyone
else who does yet). Instead, if/when you hit the limit, there will be a
phone number, and you'll have to call Microsoft. Explain that you're plagued
with defective laptops, etc., and they will walk you through activation over
the phone.
To be on the safe side... you might want to wait to try to activate this
time around until you've put the laptop through its paces (yeah, I know that
some things won't work until you've activated, but, still...).
One wonders, however... if you've hit two defective laptops in a row
(presumably of the same kind), whether it might be time to switch to
something else. For the benefit of those of us in the laptop market, it
might be useful if you were tell us which make/model you're encountering the
problem. You might save someone else from having to go through the same
painful experience.
