Are you getting Error 810003c1: “We were unable to sign you in to the .NET Messenger Service” when trying to sign in to Messenger recently? Microsoft has cut off several countries from using Messenger, countries that are embargoed by the United States. These are: Cuba, Syria, Iran, Sudan and North Korea. The Windows Live Team says:
Microsoft has discontinued providing Instant Messenger services in certain countries subject to United States sanctions. Details of these sanctions are available from the United States Office of Foreign Assets Control.