instalation key

I have a mid-2009 MacBook Pro that is in like-new condition, but the OS is dated (maxed out at El Capitan), so I cannot install the latest browsers (and the security that comes with an up-to-date browser). Parallels Desktop seems like the perfect workaround for this problem, so I went to the...

I just bought an instalation key, but now Parallels is asking me for a previous license... Just realized i bought an upgrade version... how does the system allows me to buy an upgrade whithout having a previous license? Well... gotta solve this... please, cancel my purchase so i can buy the...