How is it possible that all your software broke?
Every major software vendor (Microsoft, Google, Adobe, Mozilla, Valve, Spotify) has designed their applications to run seamlessly under Standard User accounts for over 15 years.
If everything failed, you are either, exclusively using abandoned shareware from the Windows XP era that ignores all modern file hierarchy rules, lying about the scope of the failure, or you completely botched the migration.
My bet is on the latter. You likely didn't just "demote" the account, you probably created a new account or messed up the ownership of your user profile folder (C:\Users\<Name>).
If shortcuts disappeared and settings vanished, that isn't the software "breaking." That is you trying to access the private data of Admin_User from the profile of Standard_User.
I don't think I said all. Did you read where I stated all, as in every piece of software failed to function? I don't think I said that, but if I did say that, or if I implied that, my apologies, that would be incorrect. Lastly many software's don't give the option "install for all users".
Thanks for your attention to this matter, you seem very bright. I do agree with all your points, just not sure, even though I tried, that I can fully implement a user account with any success.
