To start and use and configure the services of Mercury Mail
as the administrator from localhost
you don't need a password or even need to change one.
User accounts of the mail and ftp services you offer to your clients do however need a user/pass combination and these are set up and configured or changed in the Admin...
panels of either program and are accessible from the XAMPP Control Panel
after the services are have been started and are running.
For some good reading go to the link below and register to view the excellent XAMPP Tutorials.
After registering click on the XAMPP - Tutorials in the left frame menu bar.
Here is a link to another Mercury Mail how-to that might come in handy.
http://www.tech2all.com/2006/03/12/how- ... il-server/