Web Expressions login error

I am trying to sign into my website via Microsoft Web Expressions. However, I am getting the below message. I've never had any issues logging in until my computer froze up on Friday. I've re-installed the software again, but i am getting this same message.. any help would be appreciated.

Message: Unable to open site. Possible causes 1.The web server may not have the FrontPage Server Extensions installed. 2.The web server may be temporarily out of service. 3. if you are connecting through a proxy server, the proxy setting may be incorrect. 4. An error may have occurred in the web server.