XP enables you to let other people take control over your computer remotely. The intention is that you can get remote help from someone you trust, and that they get the same level of control over your computer as if they were present in your office. To use this feature they also need to run Windows XP.
When you invite someone to help you they are notified by email or an instant message (Windows Messenger). It is actually very fast and easy to set up a connection. First you choose whom to ask for help.
When contacting the assistant with Windows Messenger the connection is set up as soon as he clicks on a link reading "Accept" in the message. If email is used a small file is attached, and opening it let him set up the connection. You must provide the password in the email.