One of the things you must learn to do as a computer user is to change a network password on Windows since a local password can be set to expire. The procedure is similar when you need to change a network password on Windows but unlike a network account which can be done from any system on the network, you must do it on the computer in which has the account.
To start, you must log into the computer with the unlocked account and current password. When you arrive at the desktop, carefully press Ctrl+Alt+Delete (Ctrl+Alt+End if attempting over Remote Desktop) and wait a few seconds. A menu should then appear where you can then click the Change Password option. Enter your current/old/temporary password in the first line, the new password in the second line, and repeat it in the third line, then click on the right arrow button to save the password.