You cannot start Windows Live Messenger 14.0 after you install a Windows service pack

After you upgrade your operating system to a newer service pack, you cannot start Windows Live Messenger 14.0 on the computer.

For example, you upgrade Windows Vista Service Pack 1 to Windows Vista Service Pack 2 (SP2). If Windows Live Messenger 14.0 is running when you install Windows Vista SP2, it may run until you exit the program. After you exit Windows Live Messenger, you will be unable to start the program again. If Windows Live Messenger 14.0 is installed but was not running when you install Windows Vista SP2, Windows Live Messenger will not start.

When Windows Live Messenger detects an operating system upgrade, Windows Live Messenger will try to repair itself. This issue can occur because Windows Live Messenger 14.0 tries to use an incorrect Microsoft Installer package during the repair process.

This is a known issue with Windows Live Messenger 14.0. Under normal circumstances the repair will complete and Windows Live Messenger will run as expected.

To resolve this issue, download and reinstall Windows Live Messenger.

Important Do not uninstall Windows Live Messenger before you reinstall it.

To download Windows Live Messenger, visit the following Microsoft Web site:

Microsoft is researching this problem and will post more information in this article when the information becomes available.