Return the computer to its original state - is it?

Question

Windows

In Windows 10, "Reset this PC" is the same as a clean install of the operating system? Or if viruses/malware have infiltrated the system, the Reset PC feature won't remove them?

Answer 1

is this equivalent to a clean install of the operating system?

Yes

Or if viruses/malware have infiltrated the system, the Reset PC feature won't remove them?

no one can guarantee that 0-day vulnerabilities will not overtake you in any position, at any time, in any place
ps unless we can assume that resetting the system greatly reduces the likelihood of re-infection for most threats

Answer 2

Return to the original state is, in fact, an automatic reinstallation of the OS from the distribution package located in the recovery partition.
It is carried out in two versions.

1. With saving files - just reinstall without cleaning the disk.
   
2. Without saving files - reinstall with disk cleanup. The system is put on a blank disk
   

Or if viruses/malware have infiltrated the system, the Reset PC feature won't remove them?

With the first option, it may not be deleted, but it will be made inactive.
The second option is to remove it.
Viruses and malware are common software. And this software works only when someone installs it into the system or launches it. After reinstalling the OS, even if this software remains on the computer in the form of files, it will not work. Until someone starts it.

Answer 3

From the point of view of the "cleanliness" of the OS from malware, installing anew and returning to its original state are, perhaps, equivalent (although there are nuances: the protection of vendor and Microsoft distributions from infection, PMSM, is not the same, the second is more reliable).
And according to the results obtained, the difference is this - when you install it again, you get an empty OS (without anything at all), and when you return to its original state, as a rule, you get an OS stuffed with all sorts of vendor additives. And most users clean out these additives afterwards.
So if you really want a clean OS, then it's better to install from the MS distribution on a formatted disk.