yeah, I kind of knew / assumed that but thought I'd ask. I think you're talking about SIDs? I guess HP sets an initial password and doesn't bother telling the customer what it is.
I did go in and either removed or set a blank password. Not sure exactly which. Went through the password change and did not enter anything in any fields. Doing that I can run:
runas /user:administrator cmdand when prompted for a password can just press the return. That didn't work with the original / HP setting.
Actually a machine might have a visible password. Microsoft still supports the autoadminlogin, defaultuserid, defaultpassword registry keys for an automatic login.