Need help on parallels trial window

We just recently got a macbook from our neighbors garage sale. I've wanted to install Parallels on my mac, so I got the trial. Later our neighbor came over with a bunch of CD's for the mac like Microsoft office and Parallels. I installed the CD and when the window came up for the activation key, it said trial version and I wasn't doing to trial. Can anyone tell me how to change the trial window to a window where I can enter the activation key? When I entered the activation key, it didn't have enough digits/letters to fill up the whole space.

 

Please try to match the version? what Parallels Desktop version do you have now? i suppose it is PD7. What license do you have on the CD? is it PD7 or PD6? so it mattes - key for PD6 will not wok with PD7. And actually on every start Parallels asks if you wish to enter a permanent key - just click yes and put the key in the appropriate field.