Change Windows 7 Password Without Knowing Current Password:

If you have access to any windows account then you can change the password without knowing current password.

How to Change Window7 Password without Knowing Current Password:
1] Go to Control Panel and Find Administrative Tools & Open It.
2] Under this section double click on Computer Management .
3] Select System Tools from right window pane.
4] Under this, just double click on Local Users and Groups and then double click on Users
5] Now you will see all the login accounts of your computer. Right click on any the account whose password you want to change and then click on Set Password .
6] A warning message will popup on your screen just click on Proceed button.
7] Now enter your New Password and click on OK button.

That's it! your windows 7 password is changed without knowing current password. The only limitation of this method is that your current  account should  have atleast Administrative privileges.