80072745 or 80072746
Error Message:
We were unable to sign you in to the Messenger Service, possibly because of a problem with your Internet connection.
Error code: 80048420
Extended Error code: 80072745 or 80072746
Reasons:
Zone Alarm or other firewall programs are blocking messenger
Port 1863 is blocked by the router firewall or your ISP
Resolutions:
Zone Alarm users:
1. Open Zone Alarm's Control Center.
2. Click IM Security or click Security to open the IM Security settings window.
3. Click the Main tab or the Status tab.
4. Turn off IM Security.
5. Sign in to Messenger.
Other firewall programs:
1. Temporarily disable your firewall or contact the manufacturer for additional help.
Router settings / ISP settings:
1. Directly connect your modem to your computer to determine if the router is causing it.
2. Configure the router to make sure that port 1863 is not blocked.
2. If you can't do it, contact your router manufacturer / ISP for assistance.