Replace Your Computer
Most people have either Windows or Apple as their computer operating systems. Both of these systems continually spy on their users and thus should be replaced with an open source operating system. But the average user will need someone with technical expertise to help install that new system. And he will have to learn to use it.
My View: Linux Mint is the Best Alternative Operating System.
The Linux name is found on a number of free, open source operating systems that are based upon the Linux kernel.
Linux Mint is widely considered to be one of the best Linux distributions, both for its ease of use and for its reputation for online security. The Windows operating systems have interminable security holes, the result of Windows having the ability to run many kinds of software. These security holes are constantly being exploited by hackers. Apple has much less of a problem with hackers, but Linux Mint is more secure than either Windows or Apple. Most importantly, however, when it comes to Linux Mint, or any other Linux distribution, there is no corporation that uses their operating system to spy on you. Open source code means that the operating system can be publicly examined and that any flaws, or hacks, can be publicly discovered.
The Cinnamon edition of Linux Mint is considered to have the easiest learning curve for those used to running Apple or Windows.
Other Linux Operating Systems
There are other Linux operating systems that can be recommended, both free and commercial versions. But rather than examining those operating systems here, we would direct the user to explore them on his own, if possible with help from someone familiar with those systems.