I don't know there is a maximum number of times you can *activate* the
product - but there is a limit on the number of times (e.g. 25 times) you
can launch and use the product before you have to activate it to continue
using it.
Try Help > Activate Product; it should simply and quickly (less than 30
seconds) activate over the internet. If it was already activated, it would
soon tell you so. The only thing I can think of that would give you this
message you're getting, is that it thinks you've installed on different
machines or too many machines - outside the conditions of the EULA. I
think the EULA allows installation on one laptop and one desktop per
licence/user for FP2003.
So in effect *two* activations would be the "maximum". But again that
depends on the specific EULA.
Otherwise, you may have to activate on the phone, and from what I've heard
on other MS newsgroups, it's just an automatic/automated message service and
you don't need to talk to a Customer Officer.
Out of interest, what was the reason for the multiple-reinstalls?