I would not be wrong if I say that most computers these days are 64 bit. 64 bit offers many advantages over 32 bits and in general there is not much sense to install 32 bit OS pretty much anywhere, except maybe for some 32 bit virtual machine with less than 4 Gb of RAM, because in general 32 bit OS takes less memory. But even then, it is better to have 64 bit and just have couple of services running on it.

But at the same time, it is still common to run 32 code on it. For example, if you have IIS in many cases it has sense to run 32-bit worker process. Main reason behind that 32-bit