OK, here is where I am and I appreciate all the input. Uninstalled and reinstalled WP12. Deleted all of the music files manually in the WP library, since that had no effect. Reinstalled again and eliminated the folders it was looking to and it deleted all the library files by itself. Cool. That was my first problem and it was solved.
I have a 120GB file that I am now trying to get WP12 to take to its library. The scope of that has not changed since I want to delete the library in fact many were duplicated (the reason I wanted to clean this up), so it should work right?
Well after getting about, I would say 75% uploaded into the library, I get a message
WP12 has stopped working, thus not getting all the files
On WP12, in the music library, it became duplicated. For that reason, I wanted to clear the library and reupdate it to eliminate the duplication.
Despite removing all folders that MP12 referenced in the library, the library remained unchanged. I thought that uninstalling and reinstalling MP12 would clear the library. I uninstalled and reinstalled MP12, but it did not clear the library. I then deleted the files in the library manually (took a while). Then uninstalled and reinstalled MP12 which now has a clean library, no files at all.
At that point, I want to repopulate the MP12 library with my 120GB music file. So, I go to Organize, Manage libraries, music and I add the folder containing my 120GB of music. WP12 starts happily populating the library with this folder. HOWEVER, it stop about 75% of the way through and says "Windows MP12 has stopped working". I have tried this several times with the same result.
Note that now MP12 will clear its library if the reference folders are removed via Organize, manage libraries, music, remove folder.
I need to get MP12 to completely populate the library with my 120G folder and not stop 75% of the way through.
I don't think dragging is an option with a file that big.
Does it always stop at 75% if that is the case do what Caperjack suggested. Do a virus Scan to make sure it is not a virus problem that keeps on hindering your transfer of files into the library. See this link as well. Not sure whether that will help you but you can give it a try.
I kind of played off caperjack's suggestion, my rational was if I need to split the file to make it "easier" on MP12, maybe I could just stop it (X out) after it ran a while, and then restart it. So, I did that and it worked. Finally got the whole 120G. I guess the 120 was just to big a bite for the MP12 to chew in one seating, hence the advice on split files and what I did.