ciemnogrodzianin: You should really check how it works now, especially Linux Mint. For me it's pure simplicity these days. For most of casual users Linux is much simpler and intuitive then new Windows editions, really. I love that system for 15-minutes instalation (in live mode you can e.g. browse the internet, when your system is installed in background) and how classic the desktop environment is.

My mother, with no Linux knowledge, who has some old laptop for very casual web browsing, uses lightweight Lubuntu for a few years and faces almost no problems. It works like a charm despite of poor hardware, it's super-safe and always up-to-date (it's also hard-to-broke-something;) - Windows would never reach such state (well, it would never boot up on hardware like this).

The main reason I've switched to Linux was performance - instead of 10-minutes booting and permanent issues I've got beautiful, responsive system. All my hardware magically came back to life. The reason I've stayed with Linux is configurability - once I was able to put everything my way, I was never able to come back to golden cage of Windows, where things are changed without asking you for permission.