Messenger Help & How-to
You can choose to appear offline to some people, groups, or categories, while continuing to show your online status to everyone else.
Sign in with your Windows Live ID.
Right-click the name of a person, group, or category, and then click Appear offline to this person, Appear offline to this group, or Appear offline to this category.
If you want to send an instant message to the people you're appearing offline to, you'll need to show your online status to them again.
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