Ok, I'm on Windows 7 64bit for starters. I'm trying to get to my new employers webmail, which is https://mobile.company.com/exchange. When I get to the site I get my login box, but once I enter my credentials I get a HTTP/1.1 501 Not Implemented error. I read a quick kb on it and disabled http 1.1. Now I get a HTTP/1.0 501 Not Implemented error. I've been trying this in IE8 and FF3. I'm not sure what else to check at this point. I tried Chrome and it won't even go to the site. Any ideas? Looks like it's mostly related to the user-agent string that gets sent with the request to the exchange server. Windows 7 sends a string of Windows NT 6.1 and I'm guessing Exchange doesn't like that. Still looking to see if there's a patch for Exchange or if this is something that still needs to be addressed.