https://bugs.winehq.org/show_bug.cgi?id=50580
--- Comment #1 from winetaste@gmx.net --- Extracting the installer and editing iTunes64.msi:
There are two LaunchConditions checking for Windows 10:
1. "Installed OR ((VersionNT=601 AND ServicePackLevel>=1) OR VersionNT>601)"
2. "Installed OR (VersionNT>=603 AND BUSEROSVERSION AND BUSEROSVERSION>=10) OR DISABLE_OS_VERSION_CHECK"
Deleting the second condition fixes this problem and after more testing:
Wine returns BUSEROSVERSION=6 instead of >=10