iTunes Store "We could not complete your request" help!

I installed again OS X 10.8.5 after my hard disk failed, but when I open the iTunes Store and try to connect to my Apple Account, it keeps popping the "We could not complete your iTunes Store request." message, any solutions? It is frustating beacuse it's already like 2 months and I can't download ANYTHING. Doesn't even connect to my account.