Microsoft's Software is Malware
Malware means software designed to function in ways that mistreat or harm the user. (This does not include accidental errors.) This page explains how Microsoft software is malware.
Malware and nonfree software are two different issues. The difference between free software and nonfree software is in whether the users have control of the program or vice versa. It's not directly a question of what the program does when it runs. However, in practice nonfree software is often malware, because the developer's awareness that the users would be powerless to fix any malicious functionalities tempts the developer to impose some.
Microsoft Windows has a universal back door through which any change whatsoever can be imposed on the users.
More information on when this was used.
You might well decide to let a security service that you trust remotely deactivate programs that it considers malicious. But there is no excuse for deleting the programs, and you should have the right to decide who (if anyone) to trust in this way.
Windows 8's back doors are so gaping that the German government has decided it can't be trusted.
Windows 8 on “mobile devices” is a jail: it censors the user's choice of application programs.
Mobile devices that come with Windows 8 are tyrants: they block users from installing other or modified operating systems.
- Spyware in Windows: Windows Update snoops on the user. Windows 8.1 snoops on local searches. And there's a secret NSA key in Windows, whose functions we don't know.
I think a person or company has the right to cease to work on a particular program; the wrong here is Microsoft does this after having made the users dependent on Microsoft, so they are not free to ask someone else to work on the program for them.
As this page shows, if you do want to clean your computer of malware, the first software to delete is Windows.