Could REA help reverse engineer Windows for better performance or a free compatible implementation?

[V1nic1us]

Could REA help with reverse engineering Windows to understand its performance bottlenecks and improve components such as File Explorer?

I am interested in whether this could lead to a free, Windows-compatible implementation, or at least help make an existing Windows installation faster and more efficient.

In particular, could this approach help reduce the overhead of AI features and other background components without having to repeatedly uninstall or disable them? I would like to investigate which components actually cause slowdowns rather than assume that AI features are always responsible.

A few questions for the community:

• How practical is using REA to analyze Windows and identify performance bottlenecks?
• Could the findings help improve or replace applications such as File Explorer while preserving compatibility?
• Is a free, independently developed Windows-compatible implementation a realistic goal, and what technical and licensing constraints would apply?
• What would be a manageable first experiment or component to investigate?

My goal is to explore performance improvements and compatible alternatives, not to bypass Windows activation. I would appreciate insights from anyone who has worked on similar projects.

[GLima-n]

I'd start with performance profiling rather than reverse engineering the entire OS. Windows Performance Recorder (WPR) and Windows Performance Analyzer (WPA) can help identify CPU, disk I/O and thread activity during a reproducible Explorer slowdown.
Record a baseline, reproduce one specific action such as opening a large folder, and compare traces before and after changing one variable. This helps distinguish shell extensions, storage latency and background processes from assumptions about AI features.
REA could assist with analyzing a narrowly scoped binary or interface, but a fully Windows-compatible OS is a much larger undertaking. ReactOS and Wine are useful reference projects for understanding compatibility challenges. I'd begin with one Explorer operation and measurable latency rather than attempting an OS replacement.

[V1nic1us]

Thanks, that's a much more realistic way to approach it.

To be honest, what I really wanted was a Windows that stays compatible with games, including ones with anti-cheat, without the AI features and telemetry that eat so much memory in the background. Anti-cheat is exactly why ReactOS or Wine/Proton don't work for me, since many anti-cheat systems block non-Windows environments.

So for now I think the only practical option is Windows 11 LTSC.

[NarutoUA]

To be honest, what I really wanted was a Windows that stays compatible with games, including ones with anti-cheat, without the AI features and telemetry that eat so much memory in the background. Anti-cheat is exactly why ReactOS or Wine/Proton don't work for me, since many anti-cheat systems block non-Windows environments.

Windows binaries are signed by Microsoft and most anti-cheats won't allow you to load custom, unsigned dlls

[eliriverback]

I don't see any point in reverse engineering windows. If you would like faster experience there are distros (unofficial) for windows that have been stripped out of anything that the operating system really doesn't need.

Anyone interested in windows performance should start there. Narrowing down the services that are really essential and what the games and software would need to run and try to list the dependant libraries for software that you are trying to optimize or make compatible.

If there could be free windows it would've been done years ago. All software is running on proprietary windows components that have now been translated on Linux through compatibility layer that translates Windows API calls into calls the host operating system can handle. Wine and Proton are the examples that already make the optimization of the Windows as an operation system a fools errand because the required components already exist inside these compatibility layers.

This proves that the functionality of the windows is known so well that reverse engineering it doesn't offer anything in return. This work has been done already and the focus has shifted on these compatibility layers that already offer windows as a runtime environment without the unnecessary services or operations on the side.

EDIT: You apparently ended up in the same conclusion judging from your comment: "So for now I think the only practical option is Windows 11 LTSC." I don't think you could go much more lightweight than that. Only way to improve windows is to go and work for Microsoft. This is the way they have preserved their stance on the market since their first release.