Steam will not install on my Windows XP 64 Bit machine

[benedicto.rosa1]

I created this machine to use with MS Flight Sim. I can not for the life of me figure out why Steam will not install on my 64 bit machine but runs fine on my 32 bit machine. Please help.

[David]

What happens?

[RGX12]

The WOW64 subsystem (which allows 32-bit programs to run) in Windows XP 64-bit operates a bit differently than later versions of Windows. This is significant because I believe that there may be parts of the Steam program which run in kernel-mode (namely the anti-cheat subsystem), and since the entire program is 32-bit, that part of the program is fundamentally incompatible with 64-bit Win XP (or more specifically, with WOW64 in XP).

I derived my theory from the key facts stated here:
https://support.microsoft.com/en-us/help/896456/overview-of-the-compatibility-considerations-for-32-bit-programs-on-64

[[☥] - CJ -]

64bit Win XP isnt supported, it was never widely used to gain support and even lost it by many devs a number of years ago.

[Bad 💀 Motha]

Use XP SP3 32bit or use Win7 SP1 64bit
XP 64bit has no drivers.