Open VirtualBox and click "New" . Name your machine (e.g., "Windows 8.1 32-bit"). VirtualBox should automatically set the Type to "Microsoft Windows" and Version to "Windows 8.1 (32-bit)". Allocate Resources: Set Base Memory to 2048 MB if your host allows.
One of the most common stumbling blocks users face when searching for "VirtualBox 32 bit Windows 8.1" is the confusion between the and the Guest . virtualbox 32 bit windows 8.1