Until someone packages a Linux distro up in a very tidy fashion where the installation is basically completely automated and then automatically goes to the GUI (which really is the 'easy' side of Linux, it only gets complicated from there if you want to) at boot. It could be put on a CD that competes in price with Windows.
Actually, all of those things have already been done in some distros

The next problem is that Linux doesn't have the advertising and marketing power beihnd it that Microsoft does.
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