Сегодня решил набрать www.microsoft.com и вот что получил:

The requested URL could not be retrieved

While trying to retrieve the URL: http://www.microsoft.com/

The following error was encountered:

Unable to determine IP address from host name for www.microsoft.com

The dnsserver returned:

Server Failure: The name server was unable to process this query.

This means that:

The cache was not able to resolve the hostname presented in the URL.
Check if the address is correct.

Your cache administrator is webmaster.