Are you saying that you that you want to be able to go into Safe Mode and not have to enter your password to log on to your user account? It's common security that you can't get around a user account password that easily. I don't know of any way to make Win7 not ask for a password to log on to your user account when in Safe Mode.
If you're afraid of forgetting your password, you can always create a password reset disk. It will be able to reset your password if you forget it, even if you change the password.