Plex doesn’t add metadata to any media files.
It stores all metadata which it collects in the Plex data folder.
Which is not easily transferred to a different operating system platform.
Transferring from Windows to Windows should be doable, as long as you managed to retain all the drive letters your media drives had on the old machine over to the new machine.
In other words, each media file must be accessible under the exact same drive letter, folder path and file name as it was on the old machine.
You just need to tell Plex server the location of the old Plex data folder. This is done by editing a registry key. Details in this post: [HowTo] An extended guide on how to move the Plex data folder on Windows
