This is truly bizarre, so I will start with a screen shot of the error messages - 

Now for the truly "fun" part . . .
The laptop that this is happening on had SWX2021 fully uninstalled at least 2 years ago.
The laptop NEVER had PDM installed on it.
The error didn't start happening until I uninstalled SWX2023 SP2.0
The error happens when I attempt to open Windows Explorer or the Registry Editor.

Oddly enough, I have actually seen this error before, and was able to resolve the issue with this link:
https://www.goengineer.com/blog/cleanly-uninstall-reinstall-solidworks-pdm-client

 
Following the same steps have not resolved the issue on this laptop.

I was able to get IT to disable our A/V, perform the steps again, shut down/restart, no change.
It was suggested that I use the Microsoft Uninstaller Tool, but how do you uninstall a program that is NOT there?
https://support.microsoft.com/en-us/topic/fix-problems-that-block-programs-from-being-installed-or-removed-cca7d1b6-65a9-3d98-426b-e9f927e1eb4d 
My next thought was to save a copy of the 'SOLIDWORKS PDM Client.msi' somewhere that I can point to when the error happens.
Maybe if I can get it to 'install' I will be able to 'uninstall' it.
(I am planning to try this as soon as I can get IT to disable the A/V.)

One of the things that is rolling around in the back of my head is the dreaded "fast startup" - 

This option does not appear on the laptop that is having the issue.

I feel like there is a process that needs to be stopped, or there are .dll files that need to be deleted.

I thought that this could be related to the A/V running during the initial uninstall, but I have uninstalled/re-installed multiple times with A/V disabled.

Any thoughts or ideas would be greatly appreciated!

Todd