domain-account must be deleted

my customer has set a domain-account(name). we can enter winxp without the pass. but we will need it if we enter in save mode. an we kniow the password.the background is: 1. my customer does not want this pop-up-window anymore. and i have no winxp-knowledge how to delete it. i only know how to to do in winme. is it the same procedure? in network change to windows-registration.