Error 80072745 with Windows Live Messenger

Solution 1:
If you are connected to the Internet through a router, remove the connection to the router. Then, directly attach the network or modem cable to the computer. This will help determine whether the issue is related to a firewall setting on the router. Try to sign in to Messenger after you connect to the Internet. If you can connect to Messenger after bypassing your router, the issue may be related to router settings. Try resetting your router (Note: This may revert your settings back to factory default settings and may delete all your custom settings.). Please contact your router manufacturer's Help documentation or customer support channels to determine how to reset your router or enable port 1863 through the router firewall.

Solution 2:
If you are signing in from a corporate environment, contact the network administrator to determine whether port 1863 is being blocked inside the network.

Solution 3:
If you have Zone Alarm with IM Security installed on the computer, turn off IM Security for Messenger:
- Right-click the Zone Alarm icon in the notification area, and then open the Control Center.
-Click IM Security or click Security to open the IM Security settings window.
-Click the Main tab or the Status tab.
-Slide the Protection Level slider to Off to turn off IM Security.
Note: This procedure will change the IM Security settings for any instant messaging programs that are installed on the computer.
-Sign in to Messenger again to determine whether the issue is resolved.

Solution 4:
if you have the NOD32, just disable the personal firewall, antivirus and antispam protection.
Sign in to msn then enable it again.

Solution 5:
AVG Antivirus+firewall do this: open AVG then double click to Web Shield. Choose "Instant Messaging" and remove the pipe from MSN Protection.