iTunes is a digital media store available in Apple devices only. The store enables users to buy music, videos, ebooks as well as audio books. iTunes also serves as the application for iOS device like iPad and iPhone.
If iTunes is not working then first thing, you should check the updates properly.
If it is not updated then first, check and reinstall the iTunes in your device. If you are using Mac, then got to the preferences to update it.
Now get the iTunes and find the list, delete the list. Restart the computer, and if it will work, if not then you have to reinstall it.