my pc can not connect to itunes match?

I have Windows 7. I am unable to connect my desktop to my ITunes Match account. I have corrupt files on my Ipad, Iphone, and my desktop. I wish I had never signed up for this crap. But I need to reach some resolution and at least have one goo library of all my media. I want to do this before I have to pay for another year of ITunes Match. The syncing of the desktop, phone and tablet have always been spotty to say the least but I have songs missing and five or six copies of others.