You can remove Passports in the sign in list by clicking the Start Button, then click the
Control Panel. Then, click User Accounts in the Control Panel. Select your account name, and
then on the left side of the screen, under Related Tasks, click 'Manage my Network
Passwords'. In the window that opens, you can remove accounts by clicking the passport you
wish to delete [denoted by (Passport)], and then click the 'Remove' button.
For more detailed instructions and screenshots on this procedure, see here:
Windows MVP, Messenger
Messenger Resources - http://www.yqcomputer.com/