I burned a win7 ISO to dvd

As above I burned this to use in an emergency. As a test I used it to get to the first scree to be sure the disc could be read. I got that far. Questions are that in an emergency when I cannot use the desktop, NO password was set up, will the cd be read like the boot order screen is, in my case F9, for HP, and will the cd ask for the product key? When I use the recovery console or cd set it does not nor is activation required. The original hdd's were removed for larger drives. A key finder app revealed the same key for both desktops despite the 2 completely different key #s. Neither key works for other reasons or apps. If the cd will work like the recovery partition or the cd set, that is what I am looking for. If not I will toss it. Please tell me what I need to know if you can in detail but not in jargon. Thanks.