I'm trying to see if there's a way to detect (via html, css, javascript) when a webpage - our captive portal - is loaded from the Windows OOBE browser that is displayed when in the setup process of windows pc's. (the 'Lets connect you to a network' step) The reason im wanting to detect this is to cater up different content dependent on whether or not it is from OOBE - The reason being is that this captive portal page is for setting up access to the company wifi, but it requires additional setup (Certs/profiles) to be configured during this which cannot be done until you have completed OOBE. These are BYOD devices, not company owned/managed.
From what I can see, I believe the browser it uses is some sort of embeded internet explorer (at least on window 10). I think i can do user-agent sniffing to detect this, but obviously this would target all internet explorer instances (I know, it should be deprecated, but still..) Plus literally every source on user-agent sniffing says isn't really reliable, & is spoofed/incorrectly reported most of the time anyway.
I don't know if this is achievable or what direction I should go down really..?