Itunes cannot find tracks after move to different Macbook Air.

Some time ago I spilled beer on my keyboard and although my Macbook air worked it was slow and the drive was constantly whirring. I bought a second hand Macbook air and did a transfer. All ok but I found that when I went into Itunes it could not find the tracks of my 4000 plus songs on various LPs most of which were uploaded from CD years ago.

Now I can individually locate the songs and then its fixed but this takes about 40 seconds of going through levels of files then finding the artist then song. I have fixed about 200 songs this way. But 4500 is a lot of time.

I have done all of the things on mentioned such as ensuring Itunes media folder location is correct ie mine is /Users/Benn/Music/iTunes/iTunes Media/Music and have replaced the itl. itunes library file to a previous version.

A friend suggested saving all the songs to a hard drive then reinstalling itunes, but I am not sure how to do this or whether it would work. I obviously do not want to do something that would lose 4500 tracks.