Forget when/where some of these settings came into effect; Win7 is a bit dusty in the grey matter.
Does Windows allows (admin) accounts to have blank password; if not, need to do a REG entry or maybe a GPO setting
Account CAMERAS can be logged (kb/monitor) into without using a password; yes i know, but have to ask it
Account CAMERAS has the right/privilege to start a service
BI prompt is collecting USER and PASSWORD to set these values within the BI Service.
.\BIservice would be seen as .\Cameras on your system
For password and confirm password blank-out field and enter nothing
You may be able to enter anything you want (sic garbage) at the BI prompts, then manually edit these yourself from within Services (CMD prompt> services.msc)