I'm assuming you mean that each person who uses the computer has their own user account on the computer and their own hotmail/live address.
1. Log on to the computer as whichever user you want to set up messenger for.
2. Enter the e-mail and password for the live/hotmail account you want to use. (If you've used it before it might appear in a drop-down list.)
3. Tick all three of the boxes below the password box (Remember me, Remember password and Sign me in automatically). (If the ticks aren't there, click the down arrow on the right).
(If this doesn't work then you may need to go to tool, options, sign in and tick all applicable boxes.)
Hope this helps
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