Suggested: https://en.wikipedia.org/wiki/Itanium#History
With how long it took Intel to ship expensive, incompatible, so-so performance ia64 chips - your theory needs an alternate universe where Intel has no competitors, ever, to take advantage of the obvious market opportunity.
It was also an era where people were happily stating on PAE 32 bit x86 rather than pay the price and performance premium for Itanium.
4gb of RAM existed but many many systems weren’t even close to it yet.
I don't need suggestions for a time I live through, I am in computers since the 1980's.
Without AMD, there was no alternative in the PC world, It was already the first 64 bit version of Windows XP.
Since we're providing suggestions in computing history, I assume you can follow the dates,
https://en.wikipedia.org/wiki/Windows_XP_editions#Windows_XP...