I'm not a terribly security oriented person, and these kind of things are annoying. It also confuses the crap out of my parents who just want to get online and browse news sites.
To disable this message:
- Go to Start
- Type in "control userpasswords2"
- Select the "Advanced" tab
- Click on "Advanced"
- Expand "Local Users and Groups (Local)"
- Select "Users"
- View the user you wish to edit
- And finally, tick "Password never expires"