Well guys, I finally got this to all work. After unsuccessful dealings with McAfee and also purchasing a new usb to serial cable, I was still having issues.
I finally did a search on enabling COM ports (which is what the LSU module kept showing me under serial "not enabled". I walked through the results and had me go to device manager where I enabled a com port. Still same issue with the new cable. When in device manager, I saw an error under the com port that said "pl2303ta do not support windows 11". Did a search on that and got the windows 11 driver. I installed that. Still no luck - a new error message, that I don't recall in device manager for the com port. I did a search on that error message and came across a thread that indicated to download an older version of the driver. Which I did. Finally, success. The laptop was now talking to the Lionel base.
Now more adventures:
I went through the process of updating the black module to the 1.6 version of the base software. I then followed the install of that software onto the base. Lights were blinking, etc. But nothing. I was getting 5 blinks in a row on the yellow light on the base indicating "Module too advanced to read" - whatever that meant. It was an error shown on page 15 of the LSU manual. I pulled out the black module and went through the process again. Same blinking yellow light with 5 blinks. At that point, I pretty much gave up, but just wanted to see what now showed on the cab 2 remote.
Lo and behold - the Cab 2 is version 1.7 (which it was already) and the base now showed 1.6 (versus 1.52 - before I started this process). So, I guess I'm now up to date. I checked all my locomotives, switches, etc. All were working properly. I did notice on one of my legacy locomotives that the display on the cab 2 that shows the icons now had a new one called Aux 3. Not sure what that's for - but may investigate after I finish drinking this evening!
What a long haul this was!! Yikes. I hope I don't need to do any more updates in the near future.
Thanks all for sticking with me on this!