I stumbled across a hack to remove the query of ZwQueryLicenseValue from the NT6/7 kernel and tried it out. It took quite a lot of searching because the numerous file hosters were all being ad-ridden ...

I bought a Pro Upgrade license and reading up on it, it looks like the 64-bit version won't upgrade XP 32-bit, but will instead do a clean install (wiping out the XP install in the process).

For most would-be Windows 7 users, a 64-bit version of Windows 7 is the right move. But if you don’t have sufficient RAM (at least 4GB), or you rely on devices that don’t have supporting 64-bit ...