Bypass Windows XP login screen

First you have to make sure that you have logged into an administrative account
else you will not be allowed to make changes.
Go to “Start | Run”.
Now in the open box, delete if anything is present and type “control userpasswords2” without the quotes. If you aren’t logged into an administrative account it will ask you to login into one.
After you have done that a new window will pop up.
Under the “User” tab, you will see a check box saying, “Users must enter a username and password to use this computer”. Uncheck that box. Now if you have multiple user logins, then it will ask you which login you would like to automatically log into. Enter the username and the password if any and click on “OK”.
Restart the machine and you will directly reach the desktop.