My computer is asking me to enter a product key to open nikon caputure nx?

Can anyoneone help with this? I have a coopix P100 and installed the software and the trial period ran out but now computer keeps asking for product key. Don't know where it is. Can't open jpeg files without it because everytime i click on a jpeg file it tries to open caputure nx but won't go any further than enter product key as trial period has ended.

Simply change the file association settings so they open via a different program.

Either buy the software - ie pay the money for the product key.
or
If you don't want to buy the software just uninstall it.

Well install google Picasso or another program and use that instead.

Nikon Capture NX. Sounds like Raw developing software.eh odd.oh well you'll do fine with your JPGS in Google Picasso