Getting to setup with password

I have a Dell Dimension 4100.  When I turn it on it asks for a password before it boots up.  I know the password but I would like to remove it. When the Dell logo appears I hit ESC and it says to hit Del to run setup.  After that it prompts me for a password.  Once I put the password in, the system boots up to windows.  Is there a way I can get into the setup to remove this password?  I would like to get rid of thie compute so I have to remove the password.  Thanks!