Installing Plex onto drive D: is not moving the Plex data folder into drive D:
Uninstall Plex server completely.
Make sure that both the 32bit and the 64bit version are removed.
Remove the Plex data folder from its default location on drive C:
Remove the Windows registry branch of Plex server https://support.plex.tv/articles/201941078-uninstall-plex-media-server/
Verify that your Windows has the latest Micrososft software updates.
Disable and remove all 3rd-party firewall software.
Disable and remove all VPN software.
Check the network adapter that it is classified by Windows as “private” connection.
If you hve more than one network adapter in the machine, disable all but one. Wired, preferably.
Download the Plex server installer for 64bit
Install it into the default location on drive C: – i.e. C:\Program Files\Plex\Plex Media Server
Make sure it is working, but create only a small test library with 1 or 2 videos in it.
Once you have verified that it is working as expected, follow this guide to move the Plex data folder onto your drive D: [HowTo] An extended guide on how to move the Plex data folder on Windows
