@FranceBB @jumper @someguy25 @i430VX @VistaLover @rloew @Dibya @I41Mar @Mathwiz @aviator @RED-CHAMBER @Tamris @CoRoNe
SOLVED!
Thank you all for your troubleshooting and input. After installing a fresh Dell OEM copy of Windows XP on my Inspiron 1420, and "one step at a time" trial and error, I discovered the missing culprit:
Visual Studio 2013 (VS2013): https://download.microsoft.com/download/2/E/6/2E61CFA4-993B-4DD4-91DA-3737CD5CD6E3/vcredist_x86.exe
I tried several different things, one at a time. Once I installed this package, Audacity 2.3.1 immediately began working.
I'm thankful for this Audacity thread which helped me FINALLY discover the culprit: https://forum.audacityteam.org/viewtopic.php?p=272186#p272186
Note, my Dell XP copy is SP3 RTM with IE6. So, no further updates to Windows XP or IE are needed.