Windows Messenger includes an option that signs you in automatically whenever you are online and using Windows XP. This is great if you’re sure you always want to sign in right away, let others see that you’re online, and be available to contact you as soon as you sign in. But you may find that you’d rather control when you show up as online in other peoples’ contact lists.
To change the setting so that Windows Messenger doesn’t sign you in automatically
Click Tools in the Windows Messenger window.Click Options, and then click the Preferences tab.
Clear the Run Windows Messenger when Windows starts check box and Click OK.
The next time you log on to your computer, you will need to start Windows Messenger manually before you can use the program.
Start Windows Messenger manually
To start Windows Messenger manually follow this procedure
Click Start, and click All Programs.Click Windows Messenger.
The program signs you in and displays your contact list. Your online status is set to Online by default, and all contacts in your Allow list will be able to see and contact you.
Note: The first time you start Windows Messenger, you will be prompted to get a Microsoft Passport Network account, if you don’t already have one.