Log on with another account that has admin privileges
Click on Start and then Control Panel.
Click on the User Accounts and Family Safety link.
Note: If you're viewing the Large icons or Small icons view of Control Panel, you won't see this link. Simply click on the User Accounts icon and proceed to Step 4.
3.Click on the User Accounts link.
4.In the Make changes to your user account area of the User Accounts window, click the Change your password link.
In the first text box, enter your current password.
In the next two text boxes, enter the password you would like to start using.
Entering the password twice helps to make sure that you typed your new password correctly.
the final text box, you're asked to Type a password hint.
This step is optional but I highly recommend that you use it. If you try logging in to Windows 7 but enter the wrong password, this hint will display, hopefully jogging your memory.
Click on the Change password button to confirm your changes.
You can now close the User Accounts window.
Now that your Windows 7 password has been changed, you must use your new password to log on to Windows 7 from this point forward.
Create a Windows 7 password reset disk. While not a required part of changing your password, I highly recommend that you do this.
Note: You do not need to create a new password reset disk if you already have one. Your previously created password reset disk will work no matter how many times you change your Windows 7 password.