Docker, by default, will run on 64bit versions of Windows. However, there are some tutorials that teach you how to install it on a 32bit version. I wouldn't recommend it because sooner or later you will run into issues with the addons that will have to be installed and most of them will cause compatibility issues. However, if you want to proceed at your own risk, consider following this link. Otherwise, install a 64bit capable Windows version and continue with the 64bit version of Docker as well.