At the end of the actual Windows installation, we have often talked about it, a final phase called OBE (Out of Box Experience). This is a procedure which, through a series of steps that follow one after the other, guides users in initial configuration of your Windows device.
The key requests presented during the OOBE phase are the choice of language and region, setting up a user account, local network access, privacy preferences and a series of customizations. With the latest versions of Windows 10 and Windows 11, OOBE has become increasingly more complex. Even too much. For example with the addition of screens that have more to do with aspects related to marketing than with the actual configuration of the system (think of the promotion of Microsoft 365, OneDrive, the exhortations aimed at using a Microsoft account). By activating the unattended installation of Windows, it is possible to skip the entire OOBE part and request the setting of the operating system in a completely automatic manner, as reported in a configuration file.
OOBE secrets: what key combinations can be used
During the OOBE phase you can press the key combination MAIUSC+F10 to access a command prompt, useful for immediately changing the behavior of some aspects of the operating system. We have seen, for example, how to use the terminal window to install Windows 11 without a network connection and avoid the Microsoft account requirement.
Certainly less known is the keyboard shortcut CTRL+MAIUSC+F3 which, if used during OOBE, reboots the system into the so-called mode Audit. This is an operating mode that works in parallel with OOBE and which allows you to configure the system according to your needs before its actual installation.
The mode Audit creates a sort of “template device” that the user can configure and then create a version of Windows ISO file usable on any machine, regardless of its hardware configuration. Think about PC manufacturers: this way they can create a customized version of Windows to be deployed across millions of systems, minimizing the time required to complete the operation. After the intervention, a file is obtained install.wim custom to insert into the ISO file.
The “core” of the system is the excellent Microsoft Sysprep utility which allows you to customize the contents of the to your liking installation media of the system.
OOBE is a web application: here’s the really interesting discovery
If you try to press MAIUSC+F10 while installing Windows 11 then typing taskmgryou will notice that OOBE depends directly on the system component WWAHost.exe: this alone suggests that the entire final configuration phase is in fact aWeb application.
Not only. With a simple check, you can ascertain that OOBE is called “low-level” CloudExperienceHost and is contained in the folder \Windows\SystemApps: by accessing this folder, you realize that OOBE uses codice HTML, CSS and JavaScript. It’s all explained in the video posted by Andrew Enderman on YouTube.
Using a test system, you can for example download the Windows 11 ISO then extract the file \sources\install.wim. By opening it with the well-known 7-Zip utility, then going to the subfolder Windows\SystemAppsyou can extract the directory Microsoft.Windows.CloudExperienceHost* and analyze its content in detail. The entire operating logic of OOBE is contained in the file default.html.
As Enderman points out, OOBE contains a lot of references to legacy technologies that Microsoft no longer uses: while having fun “browsing” the contents of the folder, in fact, you notice explicit references to the now defunct digital assistant Cortana. Not only that, among the “Event listener” developed in JavaScript and contained in the OOBE Web app there is also an undocumented one: CTRL + MAIUSC + J.
The developer console hidden in Windows OOBE leaves us in disbelief
The work carried out by Enderman has brought to light what is in fact a development console left in a production environment. Try pressing the key combination CTRL + MAIUSC + J during the OOBE phase of Windows. A gray background screen will open that accepts a series of commands as input. Try typing help and press the Enter key.
Our question is: does it really make sense to leave this console, albeit cleverly hidden, in an installation procedure used on hundreds of millions of systems around the world?
As you can see here, what we find in front of us is one console JavaScript fully functional interactive interface, which allows any programmer to interact directly with the OOBE phase. It’s something truly incredible!
And it is shocking that any changes (Enderman even had fun modifying the license conditions for using Windows 11, making it playfully a software copyleft…) are immediately acquired. After a restart of the machine (for example with shutdown /r /t 0) are automatically applied.
More details on the operating logic of OOBE are available at this address.
Again, one wonders what the ratio of Microsoft’s choice: impossible, really, that i Secrets become OOBE did not emerge, sooner or later…
Opening image credit: iStock.com – NguyenDucQuang