Ive been asked for my old key, but my parallels came with my laptop?

I'm working on an old laptop given to me by my school after i graduated. i bought it through the school and it came with all these programs pre-installed, one being parallels. I went to upgrade to the new version, purchased the upgrade, installed it, logged into the window that popped up and put in the upgrade activation key, but it wants my old key from my old version, which i dont have anywhere. is there anyway to upgrade now? or have i just wasted my money?

 

You can recover your old key for parallels.
here is a decent article from parallel's forum https://kb.parallels.com/en/115424
Try the Command method & Do let me know if this worked for you or not?