XP OEM - Interesting conversation with MS employee

Last night I upgraded a customers machine with new motherboard, cpu, memory,
video card, netcard and soundcard. The only thing that was the same was the
HDD, dvd drive, tape backup and scsi card. I was having trouble with the
internet so I phoned MS to activate XP again. After it activated I asked him
what the limit is to hardware change before XP won't activate. He said that
XP oem has to always remain on the same PC to be activated. In return I
asked "what constitutes the same PC?". He kept going around in circles and
not answering my question and just stating that it has to always remain on
the same PC. He never gave me a definition of what "same PC" means. In the
end I asked if it was more of a policy than a technical limitation and he
said "thank you for calling microsoft to activate your software" and hung
up!

I suspect that means that it can be installed on a completely new machine
and will activate ok. Is that true?