Hello player10,
Thanks very much for buying the upgrade and sorry to hear about the problem.
Does the main Hauptwerk download page work for you?:
https://www.hauptwerk.com/win/
(The Hauptwerk for Windows software is the same regardless of how it's downloaded -- it's just the presence or absence of a licence that determines whether it runs in licensed mode or as a trial.)
Alternatively, if you've download the Windows version on your Mac then you could potentially transfer that to your PC via a USB memory stick.
Or if either of those are problematic just let us know and I think Francois would be able to send you a download link for it if needed. Thanks again.