Post was rewritten after additional investigation. The error message was:
Installation of this product failed because it is not supported on this operating system. For information on supported configurations, see the product documentation.
The installation target is a Hyper-V guest machine as follows: 2G RAM, 14.5 GB free on the C: drive, 2.5 GHz CPU. .NET 3.5 is turned on.
On this page https://www.microsoft.com/en-us/download/details.aspx?id=42299 the following note was confusing to me (bold is my emphasis):
Note: Microsoft® SQL Server® 2014 Express includes both 32-bit and 64-bit versions. SQLEXPR32_x86 is a smaller package that can be used to install SQL Server 2014 Express onto only 32-bit operating systems. SQLEXPR_x86 is the same product but supports installation onto both 32-bit and 64-bit (WoW) operating systems. SQLEXPR_x64 is a native 64-bit SQL Server 2014 Express and supports installation onto only 64-bit operating systems. There is no other difference between these packages. Microsoft® SQL Server® 2014 Express is not supported on IA64 systems.
The wording seemed to indicate the x86.exe would work on both 32/64 bit systems which was consistent with my findings. But I thought that also indicated the 32bit.msi would also work on both 32/64 bit systems. I am beginning to believe I misunderstood and would appreciate confirmation the error is my reading of the note.