Use Windows only for absolutely innocuous activities that do not involve anything forbidden. NEVER talk about anything forbidden through any messenger that you can install on Windows.
Never use services like Whatsapp-Web, telegram-Web or other similar services that simulate a messenger in the Windows browser (no matter which browser). Because there the end to end encryption is not 100% given.
Install Windows as the first operating system on its own hard drive, never install a second operating system on the same hard drive as Windows.
2. standard Linux distributions like Ubuntu, Debian, Suse etc..
Install them on separate disks and ALWAYS on a fully encrypted LVM.
If you only encrypt e.g. the /home partition you leave a huge gap open where data can be dug out.
Additionally install Kali-Anonsurf to route absolutely all traffic over the Tor network.
This option at least keeps your content and conversations secret and the stored data can’t be easily read.
Note: The more complicated your password is, the more secure your data is.
3. tails, Parrot OS, Linux Kodachi and similar operating systems
For your purchases on marketplaces, forum visits and other forbidden activities that are not in conformity with the law in your country
ALWAYS on USB stick, ALWAYS fully encrypted for your darknet activities.
This is in my opinion only for “small fish”, a vendor should definitely put more effort, a buyer will hardly be worth the effort to crack this encryption, a vendor may be.
4. qubes with Whonix for the highest level of security and secrecy.
There is a reason qubes is used by people like Edward Snowden, it keeps your information secret and you at large.
at least 2 VM (better more) running your traffic, or anonymously rented web servers with remote desktop as an additional option, where ALWAYS between the machines all traffic MUST go through the Tor network
any clearnet line is a security risk and must be 100% excluded
ALWAYS fully-encrypted on separate hard disk but better on appropriate USB.
Note: Qubes needs only 32GB memory, but a 32 GB stick is too small, always use 64 or 128 GB sticks.
And last but not least
If you are doing something forbidden and interrupt what you are doing, NEVER LEAVE THE CIRCUIT UNLOCKED.
Never go to open the door leaving the computer on, NEVER write your password on paper, you have a brain with memory, use it.
NEVER leave your USB stick lying around, hide it well, best outside your home.
last but not least. Don’t tell anyone what you are doing, don’t brag about how secret you keep your activities and especially don’t tell what tools you use.
Any confidant is a security risk and can land you behind bars.