log on screen problem

I have a Dell Dimension 2400 with Windows XP I am helping a friend with. I wanted to get rid of the log on screen on start up. I used "run" command "control userpasswords2" and unchecked the "user must enter a username and password" box. When I restarted the computer, the log on box appeared with an unknown name in the user box. I tried clicking ok and received the message "System could not log you in. Make sure username and domain are correct, then type your password again." I tried typing in "admin" and got the same message. There is no password or user names set up on this machine. I have tried safe mode and get the same screen. How do I get past this? Or, how to reload windows xp without signing in. Thank you for your help.

Home or Pro?

And as to a worse case scenario do you have the Dell Restore CD?

The built-in account in either case would be User: Administrator Password: blank (as in nothing).

If XP Home this account is only accessible in Safe Mode. In Pro hit Ctrl+Alt+Del on the startup screen.

I was able to sign in under administrator in safe mode, but not in normal mode. I don't know where this default name on the log on is coming from. It is the original owner, but she hasn't used the computer for a couple of years. I checked the user account in control panel, and only admin is listed. I also checked in the program accessed by "run", "control userpasswords2". The only user names in there is admin and guest. I am going to reinstall windows tomorrow. Hopefully this will clear up the situation.

Home or Pro?

In either case there is a built-in Administrator account. As mentioned this account is only accessible in Safe Mode in XP Home and in Pro you need to Ctrl+Alt+delete to access it.

When XP is installed you are asked to create a User account and this becomes the Administrator account that is generally logged into. Hence you have two Administrator accounts.

Anyway via either one you should be able to Create and/or Delete other accounts as long as there are two functioning Administrator accounts.

If you don't want to reinstall create a new Administrator account and delete the old one that was previously created. You cannot delete the built-in Administrator account but under normal circumstances no one ever knows this account exists to begin with.

I should have mentioned it is the home addition. I will give that a try tomorrow, I am a little window worn today. I prefer not to reload windows. Thank you very much.