Windows 7/8/10 32-bit with Multiboot

Multiboot allows selecting either 64-bit or 32-bit Windows at startup.

If Windows is installed in one large volume  the volume can be split into two or more volumes.
1) Shrink volume by pressing Windows Flag + R.  In the Run dialog box, type DISKMGMT.MSC and click Ok or press Enter key.
2) The volume can now be split into multiple volumes by right clicking on it.

Ordering Windows 10 from Microsoft you get both the 32-bit and 64-bit versions.   It can be downloaded or sent to you on a USB drive.

If downloading be sure to download the 32-bit version.

When asked use custom install and select the new empty volume you created by splitting the volume.

This would typically be Windows 10 (64-bit) in volume 1 and Windows 10 (32-bit) in volume 2.