Hi venomblade,
According to Windows Live Help, it could be because your Windows Firewall is disabled.
1. Uninstall Windows Live Essentials.
2. Disable any firewall of security software you may have.
3. Enable Windows Firewall in Control Panel > System and Security.
4. Download and install
Windows Live Messenger 2009.
Source: http://windowslivehelp.com/thread.aspx?threadid=b...-aef7-e49859aee1d6
Source: http://social.answers.microsoft.com/Forums/en-US/...-a876-d7b7eec7f525
If that doesn't work and you still believe it's due to a registry problem, you can remove Windows Live Essentials, then save and run this registry file to remove all of Messenger's registry settings:
RIGHT CLICK HERE > SAVE. Finally, download and install WLM and the installer should create new registry settings.
Source: CookieRevised's guide to Completely Removing MSN/Windows Live Messenger