The Lock dialog allows you to lock various features in mIRC.
This allows you to set a password which locks the options in the lock dialog.
Ask for Password
If this is turned on and you have set a password by using the Lock button, mIRC will ask you for a password each time it is run.
This allows you to disable features relating to Sending/Receiving files and the Fileserver.
You can also disable private messages and dcc chats, useful if you want to limit conversations to public channels.
Hide tray menu...
This hides the list of channels/queries in the tray menu when mIRC is locked and minimized to the tray.
This hides any currently visible Tips when mIRC is locked and minimized to the tray.
This feature allows you to limit the channels that mIRC can join when on IRC. mIRC will only be able to join the channels specified in this list. mIRC will also only list these channels when you try to retrieve the full channels list via the List Channels dialog.
Note: If you hold down the Control key when you minimize mIRC, it will ask you for the password when you try to open the mIRC window later. If you use Control+Minimize with no password set, mIRC will ask you for a temporary password.