Well I'm not understanding well your problem...
I suppose the right thing to expect to happen is after you click the contact us link appear a body of an email message to fill in. If instead it opens a login box, it means the Mail client application needs you to authenticate, which shouldn't happen if you "normally" entered on your computer. So your problem should be between the login on your Computer or Network environment and the Email application itself. You wipe your hard disk recently are you sure you put back together the setings of your profile email to your application email client? It helps if you describe what Operation System and email application you have... i know this is doesn't help too much but "I" need more details about your problem at least to understand it.