dell computer running windows xp professional got from goodwill

I got a dell computer that was from a school. picked it up from the goodwill. When I got it home, it is running windows xp professional and has the ctrl/alt/del thing. I used Hirens cd to try to go around the password. It worked on a previous computer that I had. I cannot seem to get it to work on this computer, still calls for the password. I was wondering if there is another program that I can download or is there something else that I can do to delete and access this computer, any help would be appreciated. Thanks in advance.

 

try this link http://ophcrack.sourceforge.net/

also if you boot in safe mode and go to control panel>user accounts>change password and don't input anything there it should do the trick