Please select a broken track.
Press Ctrl-i to Get Info.
Say no when asked to locate the file.
Look at the location given on the summary tab.
Please post back the precise path listed there & the true location of the same song. With that information I should be able to suggest the most efficient way to fix your library.
I don't have any broken tracks. When I look at my music library, it contains only 12 albums all of which are located in the cloud. I'm not sure exactly how they got there, but I'm pretty sure they all come from one built-in play list. None of the rest of my music shows up at all.
I should have mentioned earlier, I was moving from a system running Windows XP and iTunes 10.something. (I forget the exact version, but could go look it up if it's important. My newer system to which I've tried to move my music is running Windows 7 and iTunes 126.96.36.199. (In following the instructions for moving the music, I downloaded the latest iTunes version I could get.)