Split from this thread.

Same for me except my windows live mail (hotmail) will open sometimes with no error, but mostly not without the error: 

"Unable to send or receive messages for the Hotmail (xxxxxx) account. To send and receive messages in your Hotmail account, go to http://hotmail.live.com on the Web, or try again later. To get help from Windows Live Customer Support, go to http://support.live.com and click Windows Live Mail in the list of services.

Server Error: 400
Server: 'http://mail.services.live.com/DeltaSync_v2.0.0/Sync.aspx'
Windows Live Mail Error ID: 0x80194190"