Windows 7/8 32-bit with Multiboots

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
2) Right click on the new unallocated space and click New Simple Volume. 

Windows 8 upgrade from Microsoft (you get both the 32-bit and 64-bit versions when ordering from Microsoft) 
We  recommend ordering the DVD's rather than the download.

If downloading be sure to download the 32-bit version.  Again, we suggest ordering the DVD's.
When installing, boot from the DVD, when asked  use custom install and select the new empty volume.

This would typically be Windows 8 (64-bit) in volume 1 and Windows 8 (32-bit) in volume 2.