osql -Eto log on, then use
sp_passwordto change the
saaccount's password. Remember password or note it in a secure place. Change back to the appropriate security mode and you're set. You'll need to first stop the MSDE or SQL service, plus close out any apps (including VS) which might be using the services. There's a good article covering this on Microsoft's help site. I stumbled across this while looking for something else, because I'd never, ever forget a password. That's my story and I'm sticking to it.