How to change windows 10/8/7/Vista password without knowing the old password
If you are already signed in to Windows 10 with the local account but you suddenly can’t remember the password, the two ways described below will allow you to change Windows 10 password without knowing the current/old password.
Way 1: Change Windows 10 password using Local Users and Groups
Step1: Open Run and type “lusrmgr.msc”
Open Local Users and Groups.
Step 2: Click on the “Users” folder on the left-side pane to show all user accounts.
Step 3: Select the user account whose password you need to change, right-click on it, and select “Set Password”.
Step 4: Click “Proceed” to confirm that you want to change the password.
Step 5: Type your new password in the “New Password” and “Confirm Password” box, and click “OK” to apply it.
Way 2: Change Windows 10 password using Command Prompt
This way only works when you are already signed in to Windows 10 with an admin account or when you have administrative rights.
Step1: go to start button and type command prompt
Open the command prompt as administrator.
Step 2: Type net user <username> <New Password> and hit Enter to change password for the user.