CANNOT logon

My brother was trying to find out if he could create a second user on Microsoft 2000 professional edition, so he went into control panel and accidently deleted the user profile. Now whenever the computer is rebooted, it goes straight to the log in screen and asks for a password. Everytime I have ever logged in previously was simple because I could just select cancel at the logon screen and then access was granted. Now cancel is not an option; there's a default "user" username and it prompts me for a password. The message that comes up is:

"The system could not log you on. Make sure your user name and domain are correct, then type your password again. Letters in passwords must be typed using the correct case. Make sure that Caps Lock is not accidentally on."

I have no idea what to do because no one has ever imputted a password to gain access to our computer, and my brother did not create any password when deleting the user. I don't know how to fix this problem because there is no way to access the computer to fix it. Please help me, I would appreciate it very much. Thank you

 

Thanks a lot for the quick reply!
I'll try that.

 

I went to the link you have provided, but it says that I need to edit a registry, and it also says that you do that by selecting Start and the Registry editor program. How do I edit these registrys when I can't log in to windows?
Again, thank you for your time.