I used to use a linux based floppy for reset forgotten local passwords on Windows machines. I haven’t really kept up with whether those solutions still work or not, especially since they do not really seem needed any longer. There are a couple loopholes in the Windows 7 login interface that can allow you access to an administrator command prompt to issue a “net user” command to change the password. Both use the same kind of procedure. One replaces the sticky key command and the other the shutdown/restart button action.
Boot off of your installation DVD.
Proceed until you get to the second or third screen, and select “Repair your computer.”
This will then detect your Windows installation, and bring up a menu with five or six options to choose. Select the “Command Prompt” option.
From the command prompt, you are going to create a backup of the files you are going to replace with the command prompt executable.
Sticky key option:
copy D:\WINDOWS\SYSTEM32\SETHC.EXE D:\
copy D:\WINDOWS\SYSTEM32\CMD.EXE D:\WINDOWS\SYSTEM32\SETHC.EXE
or
Shutdown/Restart button option:
copy D:\WINDOWS\SYSTEM32\UTILMAN.EXE D:\
copy D:\WINDOWS\SYSTEM32\CMD.EXE D:\WINDOWS\SYSTEM32\UTILMAN.EXE
Exit out of the Command Prompt and reboot.
Once the machine has rebooted use the following to access the adminstrator Command Prompt.
Sticky key option:
Press the Shift key five times.
Shutdown/Restart button option:
Click the red Shutdown/Restart button in the bottom right corner of the logon screen.
Once you have the Command Prompt up enter:
net user MyUserName MyNewPassword
You should get a message stating that the command completed successfully.
Don’t forget to copy the backup SETHC.EXE or UTILMAN.EXE in the D:\ drive back to D:\WINDOWS\SYSTEM32.
copy D:\SETHC.EXE D:\WINDOWS\SYSTEM32\
or
copy D:\UTILMAN.EXE D:\WINDOWS\SYSTEM32\