i can't open iTunes

Hi guys, I'm going crazy with iTunes; this is my problem: in January I bought Windows 8 (I had windows vista); at the first times I had not problems with iTunes and the synchronization, but it's a month I can not open iTunes and when I can, Itry to connect my ipap but the program gives me the error "the program has detected an iPad, but it has not been correctly identified. disconnect and reconnect iPad"; help me please, I do not know what to do... thanks everybody 🙂