Product key on old computer [View all]

Okay, so I have a old computer around 2007-2008?

Word version is 2007.

I have never used Microsoft word, I have used word pad and such.

I now need to use Microsoft word.

I cant find my product key.

I opened up word.

I clicked on word options.

I clicked on resources

I clicked on about.

It had Product Key:

But the rest was blanked.

Is their any other way they can find their Product key, so I can use word?