itunes keeps crashing, can't open or use at all

Last few days my itunes has been crashing every time I open it. I thought it was because an update was missed and never installed so I installed it and restarted my computer to ensure it took but itunes keeps crashing. It opens, tries to access the store and closes and I get a message it's crashed with no solution found. Any ideas on how to fix this? I do not have windows 10, still waiting for my copy to come in, I have 8.1. I've never had an issue before so I don't know what to do.