==================== General Method======================
Just press alt+ctrl+del 3 times.when you see the welcome screen and type administrator don't type any thing in password block and then press alt+ctrl+del 3 times and press enter you will be in administrator account
==================== Professional Method ======================
You need to use windows XP Recovery Console to copy SAM, SYSTEM in Config File.
Process : Boot from Windows XP disk, There will be an option press are to go to Recovery Console.
If you don't want to boot from disk then use the second process written:
Step-1 : When you reached your desktop main screen.
Step-2 : Put Windows XP disk.
Step-3 : Go to Start -> Run , use the following command
D:i386winnt32.Exe /cmdcons (here d means your cd drive letter which may be different in your computer)
Step-4 : Restart your computer. Now you will get 2 options either to start your windows XP or start Recovery Console.
Step-5 : In order to use Recovery Console you require By default Administrator Password, if you have no password then just press enter when it ask for password.
Step-6 : There you can copy SAM, SYSTEM from Windows/Repair directory to Config directory
Step-7 : Windows/Repair directory contains SAM,SYSTEM, Software,SECURITY which was created at the time of windows XP Installation.
