If You want to hack your friend computer which have a windows xp account than sometime its very easy when his/her admin account is not his/her active account but its activated in his/her computer.
This Administrator Account is Created during The Installation of Operating System and remain hidden inside the OS.
So if Your friend is not care about it than you care..
Here is the very easy Step....Go to Login Window, its very easy as you start your friends computer it will be in front of you within few minutes..
Now Hacking Starts..Press CTRL+ALT+DELETE two time consecutively..
A new window will appear.Their in user field type Administrator and hit ENTER key...If its Works Than BINGO..Enjoy...
