How to infect Windows:
1. Install Windows.
2. Do not install anything but Windows.
3. Place Windows machine on public network for 30 minutes.
Done!
Just surf the internet with a windows machine. Infected.
I say this with compassion, not malice. Twenty-five years or more have passed since I installed Windows 3.1, I've never installed an anti-virus program, and I've never been infected by a computer virus. Why? I don't visit porn sites, gamer sites, or hacker sites, and I never open files sent by email, other than pictures. A LOT of people I know have the same experience. I know a few people, usually men going to suspect sites and women opening cute attachments in email, who have had to reinstall windows. So, sincerely, I make the observation that snarky comments do not exhibit Mensa membership nor reflect real world experiences by many satisfied users.