I was wondering, what is the most powerful operating system in the world I bet there is something better than windows, that runs faster, better and has not so many viruses, does anyone know ?
An operating system does is not worth even a cent if it cannot run your applications.
OTOH, "performance" is something you have to define for yourself, in the same way you define "best performing car".
I was looking for something I can use for gaming, design, browsing online, and to have a compatible external pci express.
From your other posts - it seems you are into gaming. Stick with Windows (7, 8, 10 - whatever you like).
Yes, you have to spend $100 (or order your laptop with preinstalled Windows, it will be cheaper).
But in terms of speed, gaming, response, bugs, how many pages I can open online and surf and also how I can modify the interface which one is the best?
Reread my post. For gaming - Stick to Windows. There used to be utilities for "skinning" the Windows interface, but don't expect a lot.
If you want to open hundred tabs in Chrome - get more RAM. If you want 3 monitors with 4k - get most powerful pair of GPUs, and stick it into i7-7600K.
Your question does not make sense - compare it with car questions above.
I want the windows to be good at gaming, programmng all of that, to be as like a multi versatile car and I was thinking of a hybrid between windows and linux. To have best part from bost in terms of performance, gaming, viideo editing, programming, photoshop and things like that. All the features that an operating system needs to do.
There is a sticky about dual-booting.
Running one OS inside another - download VirtualBox, then search and download a ready-made Linux appliance. YOu can start from here.
And for your own good: Try to think / research the subject before posting a (silly) question.