Devek,

I think the free upgrades are for the person that bought the software. If you click on the Software Support Center tab at the top of this page, and scroll down, you will see a line of text that reads:
"Note: You must have purchased our software to access the Customer Care Center. Order Now"

I suggest you contact CoffeeCup directly via email or call them. The contact information is located at http://www.coffeecup.com/contact/ where you will also find a form you can fill out for assistance.

The software would have been registered to the original owner of the computer. Since you are not that person, there is no way for you to continue with free upgrades.
You say you don't know who owned the computer before you. You "inhreited" the computer, so ..... you got what you got, however you got it.

That is correct. The license was to the original owner of the software. This license is not transferable. You would need to purchase your own license for the software if you would like to obtain any updates.