Thanks for the response.
After further investigation, there does not appear to be
a clear method to obtain the Excel Product Id Key from
the registry due to the many variations in the registry
format for the different Excel installations.
Due to the variations in the registry format, I will
follow a suggestion and use the C: drive serial number
for the licensing. This will require a new license
whenever the C: drive is swapped out but that is
acceptable for my usage.
I also noticed the drive serial number obtained
programmatically does not match the serial number on the
disk drive box. This may be a result of converting the
text number on the box to a 9-10 digit decimal number. As
long as the serial number is a unique identifier then it
should be ok for my usage. I'll provide a small utility
to the users which they can run to obtain their disk
serial number.
thanks.
For additional details and code samples, refer to the
following thread on another forum:
http://www.ozgrid.com/forum/viewthread.php?
tid=8839&page=1#pid41886