There are many way for password hacking of Windows. But, this is the useful and easiest policy. You need live operating system for hacking.
Boot your computer by XP Live CD or Slax Live CD.Now, go to the drive where the windows are installed and enter into the system32 folder of the windows and rename the file sethc.exe to sethcold.exe. Now, copy cmd.exe file and rename it to sethc.exe. Restart the computer. Pull out the live CD and enter to the previous windows. Press the ‘shift’ button five times that is the logon screen of the computer, then the command prompt will open.
Now, to change the password of the administrator, write net user administrator 2007 and the password of the administrator will change to 2007.
If you want to open a new user without changing the password, then write ‘net user mehdi/add’ and press ‘enter’. A new user named mehdi will be created.
Now, to use mehdi as administrator, write net local group administrator mehdi/add and press ‘enter’. So, your present user can be used as administrator.
Alike, you can use any presently used limited user as administrator.