Q: Quick Time Pro 7

I cannot install Quicktime pro 7 on my new PC with windows 10. I have an enrolment key. Please help. I have installed quicktime successfully. I go to HELP then BUY QUICKTIME PRO but it only redirects me to information page and does not allow me to put in the enrolment key. I am used to this program for splicing music for an annual  trivia night then putting it on my ipod. How can I get around this?