|The error message indicates that it's iTunes that's corrupted. That may be as far as the corruption goes if other applications open okay. The fact that Windows is still running is also a good indication that the corruption hasn't affected anything else. I would expect Windows to refuse to start if corruption was widespread. |
Your music tracks are not actually in iTunes, they are in your Windows user account folder (My Music). iTunes merely keeps a library or database of shortcuts to those music tracks. The worst that will have happened is that your iTunes Library is corrupted.