This document explains how to change your Microsoft account password in Windows 8.
Move your cursor to the upper right corner of your computer screen to reveal the Charms Menu.
In the Charms Menu, left-click or tap the Settings icon.
Note: You can also go directly to the Settings menu from any screen by using the key combination Windows + I.
At the bottom of the Settings menu, left-click or tap Change PC settings to open your PC settings options in the Windows 8 User Interface.
Select the Accounts tab on the left.
A new window overlaying the Accounts screen should appear. Type your current Windows account password in the Old password field, then enter a new password in the two fields below. Click Next.
If the password reset was successful, the next screen should read, "You changed your password". Click Finish.