Did you try it? WinXP on a 32-bit Pentium 4.

Even if the CPU doesn't support 64-bit arithmetic — I don't know whether it does or not — it can still be done by software. Think about it... entire CPUs can be emulated in software.

However, I'm guessing the module doesn't use 64-bit arithmetic (hardware or software), but rather floating point numbers. They have 56-bit of precision on my system.