Administrator Account
If you are missing the original Administrator account that is made right after a clean installation of Windows XP is installed. Once other user accounts are created, the Administrator account disappears from the logon screen. So don’t panic if you’re missing it! To bring back the ‘disappeared’ Administrator account, press ‘Ctrl + Alt + Delete’ two times at the logon screen, or otherwise known as the ‘Welcome Screen.’ This will bring back the standard logon dialog. From there, you can logon to the Administrator account.
But what if you don’t want to restart your computer to access a different user account, or logon a user that you have just modified? Just click on the ‘Log Off’ button by going here:
Start -> Log Off
Now there is a box that pops up, and all you have to do is to click the ‘Switch User’ button. This will take you back to the logon screen and you can logon to a different user in Microsoft Windows XP. Good luck!