If you are looking to completely remove Plex Media Server so you can start over and reinstall clean from scratch, here are the steps you need to take to do this.
Please note, this is for Windows 10. I have never used Plex on any other OS or system.
First, uninstall plex Player (if you use it), and then Uninstall Plex Media Server.
Second, go to C:\Program Files and manually delete the Plex folder (if you use Plex Player). Then go to C\Program Files(x86) and manually delete the Plex Media Server folder.
Third, go to C:\Users\ [User Name] \AppData\Local\ and manually delete the Plex folder.
Fourth, start RegEdit, and go to the key: HKEY_CURRENT_USER\SOFTWARE\ and delete the Plex, inc. folder.
Fifth, to be safe, if you’re comfortable using RegEdit, do a search for the word Plex from the start of your Registry, deleting all entries that have anything to do with the Plex Media Server.
Be careful, in that search you will find tons of entries for words like “Duplex”, QuadroPlex", “Complexities”, etc… make sure you are only deleting entries that are related to Plex media Server.
Once you’ve finished with the registry, reboot your system, and run the Plex media Server install. You will now be installing Plex Media Server like it was the first time it has ever been installed on your system.
I hope this helps someone who screws their server up as bad as I did, and I hope it helps you rebuild your server without all the headaches I had getting mine back.
And a special thanks to tom80H The Plex Ninja for his infinite patience putting up with my noob questions and pleads for help. I never would have gotten my server back up and running without him!
Gonzo