does anybody know how to add a password before logging into msn messenger?

(example)  so nobody who shares your pc can login to your same account and see your contacts ect ect

Every .NET account (your MSN Messenger account) has a password set, you will have set it when you made your account. You should remember it from before;

Then to disable automatic sign in please look at Sunshine's reply to MSN Messenger automatic sign in.

But before you disable automatic sign in, please be sure you remember the password you set when you first made your account.
If You have forgotten it go here - https://login.passport.net/ppsecure/uisecure.srf?lc=2057&id=10
and follow the "Forgot your password?" option, and try and recover it with a secret question you set when you made your account.

thanks mate