Reset forgotten Windows password from Linux
Some times, for several reasons, one needs to be able to reset the windows password.This tutorial explains how to reset the windows admin by renaming a couple of files, it works on all versions of windows: XP, Vista, Seven and 8 both 32bit and 64bit
Important: I've used this method hundreds of times with no harm on windows whatsoever. Anyhow, a guy on facebook commented that this procedure broke his Windows installation (in a PC with UEFI). So be careful.
First, you need to download a linux live CD to be able to modify the files in windows. I will guide you assuming you download Slax and put it into a pendrive. Slax is, from my viewpoint, the easiest option because it takes a few clicks to make it ready to boot.
Go to slax.org and download slax, the 32bit version should work on every computer. Download the "32 bit ZIP" file. Now click the Documentation tab and click "Starting Slax", there you will find all the information needed to make a bootable usb and run the live linux from your usb flash drive.
Once your Slax session has started, go and click big "K" icon, then move your cursor to "Computer" and click the "Home" folder.
In the left pannel locate your windows hard drive, click it and navigate to windows -> system32. Now locate the file sethc.exe, right click it and rename it to "sethc.old" as shown below.
Now, in that same folder, locate the file "cmd.exe", right click it and copy it. Now paste it using Crtl+v, a box like the one below should pop up.
change the file name in the text box to sethc.exe and click "continue". Now we are ready. Turn off the computer. Again click the icon on the downer left corner and then hover on "Leave", there you will see the shutdown option. When the computer turns off remove the pendrive and start it again.
Wait for windows to start and when it reaches the login screen push the Shift key five times, a command terminal should appear. In that terminal type
hit the "enter" key and a window called "User Accounts" will pop up. Now choose the user you want to reset the password for and click the "Reset Password" button, set a new one and that's it!. Now use the password you just set to start windows as usual.