After installing iTunes on a fresh install of Windows, the music library was empty! Apple has a support article explaining how to get it back. I had a copy of the XML file and could use it to recreate the Library according to the instructions.
Choose File > Library > Import Playlist.
Navigate to the “iTunes Library.xml” file on the Desktop and click Open.
I also had to manually change the location of “My Music” folder in Windows as my music files are on another disk partition.