Why does iTunes stop working when I click on the menu bar?

Whenever I click the grey menu bar (artists, genre, videos, playlists, match, etc) iTunes stops working and Windows has a pop up that says it's closing. I tried updating to 11.4... but then itunes says it is missing a file or something like that and will not open period so I have to use a system restore to get it back..I;ve been enduring this without editng playlists and etc for a few months now. Please help? Thank you for any input.