EricKip68 :
Well I pulled out one of the 4GB cards and tried to load the 32bit OS and I get the same error message. I unplugged the initial 64-bit hd and tried to install the 32 bit and still nothing, I get a "No boot device available". So for grins I rebooted after replacing the 32bit with the 64bit disk and it I got "Press any key to boot form CD or DVD..." So I pressed a key and it started loading. I did the same thing after plugging the 64bit hd back in and it started loading also. So there must be something else blocking the loading of the 32bit OS.
Would you by any chance be using an UEFI motherboard? If so, the UEFI might be registering that there's a 64bit OS already installed. If the motherboard supports legacy boot options, enabling them might let you install a 32bit OS. If not, you'll want to change the boot order so that USB/CD boot comes before UEFI boot in the bios. You should be able to get the install media working that way.
EricKip68 :
FYI, my inexplicable reason is that I have two 32 bit software programs that will not operate on 64. One is a cad and the other is a genealogy software. The cad package is old but it meets my requirements. The genealogy software company went out of business some time ago and I have tons of time invested in building the data base for it and it also works just fine for my requirements. My drop back plan is to replace the motherboard in my old 32 bit Dell, that pooped out last week, and keep those two programs on it, or install XP on the new 64bit Dell and dual boot it instead of the 8.1.
Here's a few alternatives you can try:
1) Try testing the software using compatibility mode settings for Vista SP3 or earlier
2a) If you have Windows 8.1 Pro, consider using Hyper-V to run the software in a virtual machine
2b) If you don't have Windows 8.1 Pro, you can use VirtualBox
You do not want to install XP on a primary machine, it's a security liability. Inside a virtual machine with no virtual switch enabled though it's perfectly safe.