You're probably stuck

You're probably stuck with whatever came with the unit. As Kees mentioned, drivers would probably be the primary issue, along with possibly losing out on some other things. So also like Kees, I can't help but wonder why you think you need a 32-bit OS. The only real substantial difference aside from drivers, is the 64-bit version lacks any 16-bit support, which is ultimately a good thing. If you still have 16-bit programs, all of which should have been replaced probably over a decade ago if not sooner. So if that is the problem, then there's a great alternative in the form of VirtualBox paired with FreeDOS.