How to change the administrator password without knowing the old password

I am Posting This Trick For Telling You How To Change Windws XP Administration Password Using Guest Account. All You Need In This Trick Is 2 Accounts Administration and Guest. This Trick Is Only Working In Windows XP or Old Operating Systems. 
1. Go to Start and click on Run.(Or type Window Key + R)
2. Type in run "CMD" and press Enter.
3. Type "Net User" in CMD and press Enter.
4. Now you get username of your computer.
5. Type "net user username new password" and press Enter.
     Instead of word username type your username found in step 4.
     Instead of word password Enter your new password that you wanted to set to your administration account.
6. Now Restart your computer and you will able to login using administration account. 
Done. You Are Successful.