You don't have to dig into the Registry to find the "Product ID". Go to Help >
About Microsoft PowerPoint and you can find the 19 digit Product ID. That's the
number you give to Microsoft when you call them for telephone assistance.
However, that is NOT the Registration Key. Your Registration Key or Product Key
is a 25 alphanumeric character string that is on the CD sleeve or jewel case.
Actually, my personal favorite is the free Belarc Advisor http://www.belarc.com/free_download.html, which gives you tons of valuable
information about your system, including Product Keys, software versions,
hotfixes, driver versions, hardware features and capacity, etc. I think it's a
"must have".
I totally forgot about Belarc and I have it installed!!
For those not familiar it gives you your software licenses including install
keys. It also shows the tons of software you have installed...and in my case
forget about.