Windows XP has a utility which manages stored usernames and passwords for a number of programs and services located in domains other than your currently logged in one, such as such as Passport.NET, Drive Shares, etc.If the icon to manage them is not listed under your Control Panel you can still see a list of stored User Names and Passwords if you click Start, Run then Type Control keymgr.dll

From Stored User Names and Passwords you can remove stored passwords, update user account details and passwords and add new connections to servers.