2. Intro: Windows, Mac, Android etc.

2.1. Why they are not safe

Windows and Mac (but also others like Chrome OS or Android*) are:

1. NOT OPEN SOURCE and nobody can know what they actually do. The amount of weird things that these systems do without any respect to the user. Actions which the user did not ask for, who is not aware of it, actions that are shrouded in mystery and never fully explained to the user what is going on creates a severe suspicion. These corporations do not disclose what information they collect in mandatory telemetry or what they do to your device (usually under the excuse of trade secrects) and users are never let known what is going on because things this fishy in such scale would scare them off and create losses for them and it incentivizes secrecy on their part. Any and all information that they gather from their users can be held and kept in their servers forever. They usually keep track of your entire person while you use your device, collect it and sell it off to advertisers. Their "partners" buy the raw data about users and process it for advertisers and statistics to anyone willing to pay. These information packages can be bought by all ordinary people, and by the law enforcement. Law enforcement is proven to be a major customer - they use it to reduce suspect pools or gain more certainty that they found their target (when their suspect happens to share interests as that one person from that data set who also happens to live in the same town as you, who has the same buying patterns as you, who has the same search history as you): the police use them to advance their probable cause and it can and will be used to persuade a judge to sign a search warrant more easily. When you are a target it will harm you. Especially that Microsoft is taking screenshots with their AI of all screens of their users using Recall (you cannot remove Recall without breaking your entire system). Apple also hoards data of their users just about as bad if not worse than Facebook. No proprietary software is safe in current times - if it is not open source then assume the worst.

2. THEY HAVE THE ULTIMATE CONTROL OVER YOUR DEVICE. It most visibly manifests by mandatory and automatic updates that occur in the background without your consent or even despite it entirely. Windows installed AI tools like Copilot and Recall without anyone's consent. They also added AI functionality to Windows image viewer, imagine clicking it while watching CP (assuming it is not on 24/7). Updates that Windows forces on everyone revert people's configuration files after they had ran community-made scripts serving the sole purpose of removing unnecessary and scary things on Windows and Microsoft does it without disclosing the fact they tamper with your settings. This is a proof that they can install whatever and see whatever like a regular RAT, they may and will revert your settings, they always can bypass your security.

3. THEY MANDATE AI. You cannot escape AI that Windows released: Copilot and Recall. Copilot possibly listens to everything you say and sends it to Microsoft servers for analysis in a stealthy way (possibly converting your words first to text and so saving on packet size). Recall blatantly says it is a feature that it takes screenshots of whatever you are doing with pride, and that AI processes each image and learns what is going on there - so that you can ask Recall to recall for you something that you were doing but I doubt they would just lend you their computing power forever for free. They claim it is only local but I would not trust them. All AI integrations are ultimately data mining sources. If you are in the EU you can receive one extra year of Windows 10 security updates on the condition that you upload ALL your files to their cloud service, and they are known to scan it - almost certainly an AI data mining for desperate people to use these poor guys twice - once with going through all their files like burglars, and one year later with making them switch anyway. Cruel.

4. THEY MAY LEAVE SECURITY LOOPHOLES ON PURPOSE. We cannot read the code and check anything. Windows has its own encryption program called BitLocker. It is very probable that BitLocker keys are also sent to Microsoft severs because I remember that I could not find BitLocker option (as if it never existed) when I was offline during internet outage and I found it fishy. Regardless, they probably keep that key in some way and send it to their servers whenever we go back online but we cannot know. I can only suspect that they get the key this way and in case they would want to decrypt stuff on your device they can identify your device (mac address). Do not trust companies who are oriented towards profit with keeping your secrets. They will comply with the state and parrot everything on an industrial scale because their company is worth more than your 50$ license - they will not pay huge fines for their users' privacy, they can get a 1000 new users in your place when you go to jail and they will not miss you. It is safest to assume that any proprietary encryption and signing tools are guilty until proven innocent, that they have a vulnerability or that they are stolen in such dirty way as I suspect Microsoft to do. It certainly applies to Apple products and Android and anything else of that nature. As another argument: open source projects like LUKS (most common Linux encryption solution) where millions of people made sure everything is correct and secure are put under much more quality tests than probably an underfunded 20 guy team at Microsoft who are the only people who can read that Windows code and don't care about anything but salary and not getting fired, they will not care about quality of their code as much as their income source. If you have to use Windows/MacOS/Android or whatever and encrypt something - please at least use tools that are not fishy. Even Winrar password protection is much better encryption software than any of the above because they do not send that password back to their servers.
2.2. Safe operating systems: Linux or BSD - installation

There are solutions to escape surveillance and they are relatively easy. They usually require you to download the system, flash it to your spare USB drive, and just follow the nanny instructions until done.

How to go about it:
1. Consult your needs - whether you are new or advanced, whether you want to optimize or just run a system, make sure that your computer can handle that system etc. Once you know what you want you want and how much effort you are willing to sacrifice you can go to the next step.
2. Research what systems match your needs - for new Windows refugees Linux Mint is a good solution (very solid, stable and well maintained, minimal learning needed). Make sure your processor architecture can handle the system (if you don't know which installation file to pick - picking the default/top listing will 99% of times be the correct one). If you have an ancient device or very weak hardware - make sure to use light system and light solutions.
3. Download and begin the installation - go to youtube and follow a tutorial exactly as shown and it will work 99.9% of times. If you want to go with something complex like Gentoo as your first - rethink it bacause you might fail and suffer for a very long time.
4. Once installed you can custimize it as you wish. Make sure you learn to do backups! You will suffer a data loss sonner or later. Linux is not a nanny and it will allow you to destroy system files - so make sure you keep a copy of your stuff before you fully move from Windows/MacOS to your new system. I will later talk about how to do braindead complexity backups.
5. Enjoy freedom. Do not install proprietary software under no circumstances to make sure you are as safe and as free as possible.