1. From the system tray, near the system clock, right click on the Windows Live One Care Icon and choose Open Windows Live One Care to bring up the Windows Live One Care console.
2. From the Windows Live One Care window click on View or Change Settings under Other Tasks to open the Settings window .
3. In the Windows Live One Care Settings window click on Firewall followed by Advanced Settings to open the Windows Live One Care Advanced Settings window.
4. Click on the Programs List tab to view the list of programs registered with the firewall and that are permitted or blocked access to the Internet. If you see more than one instance of Messenger on the Programs list proceed to Step 5. If you are running Messenger and do not have an instance of it in the Programs list proceed to Step 6. If you have only one instance of Messenger in the Programs list proceed to Step 7.
5. If you see more than one instance of MSN Messenger on the Program List, the other instances may be for earlier versions of Messenger that were installed on your computer. Remove these earlier versions from the list by following the steps below:
5.a. Select each entry for Messenger, take note of the version of Messenger in the Version column, and compare it with the version you are currently running.
5.b. If the version does not match, click on the Remove button.
6. Add MSN Messenger through the Windows One Care firewall
6.a. Click on Add below the Programs list.
6.a. Browse to locate Messenger by going to C:\Program Files\MSN Messenger\ .
6.b. Select msnmsgr.exe and click on Open.
6.c. After adding MSN Messenger to the Programs list, the firewall Programs list will look like this:
7. To modify the access permitted to Messenger:
7.a. Select MSN Messenger from the Programs list.
7.b. Ensure MSN Messenger is set Allow access through the Internet.
For additional information on One Care go here.