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 ...

No. 64-bit Windows will not run on 32-bit architecture, and, in fact, you can't even install it. That said, you can install and run 32-bit Windows on any hardware, both 32-bit and 64-bit.

There's a difference between 64-bit and 32-bit operating systems, and it involves your PC, too.