Try this:
- Stop/quit/end Plex Server with the tray icon
- deinstall Plex Server using the regular ‘Apps’ control panel of Windows
(do not use 3rd party ‘Uninstaller’ software like Revo etc.
do not use “Registry Cleaner/optimizer” software like CCleaner et al.
Failure to heed this warning may result in losing your Plex data.) - for safety, reboot Windows
- download the installation exe of the 64bit version and install it
Are you using a method to start Plex server which is non-default?
Have you ever installed the PMS as a Windows service helper?
