I use Windows 7 because it's less buggy and prettier to look at than any Linux distro I've tried, and good for playing games. I use Linux because it's faster, lets me do things that Windows doesn't, and makes installing most things I want much easier than Windows does. I don't think either is better than the other, they both have their own merits that make them better suited to some users. And given how cheap HDD space is these days there's not much to stop a PC user from having both.