Monopolies
http://arstechnica.com/microsoft/news/2010/01/italian-class-action-suit-targets-unwanted-windows-installs.ars
Sometime back in 1998, Microsoft was taken to court over accusations of monopolistic practises. The specific reason was for their browser, Internet explorer, which came bundled in windows 98. Competitors like Netscape and Opera could not compete with something that was a part of nearly every single new computer. Because of the hidden and proprietar nature of Windows, IE could be optimized to run better. Eventually, Microsoft was hit with an antitrust penalty.
However, the REAL monopoly microsoft has is OEM (original equipment manufacturer) installations of windows. Nearly every single computer that you buy new comes with Windows. While this may be because Windows is the most popular and widely used OS, it's also because MS offers incentives for vendors to install it on a new computer.
Or, more appropriatly, Microsoft threatens companies with penalties (increased cost per installation) if they ship PCs without windows.
While many people can choose to uninstall windows from their new machine, and install FreeBSD, GNU/Linux, Solaris, UNIX, MacOSX or any other number of other systems,This does not change the fact that Microsoft has already profited on that lisence. The End User Lisence Agreement (EULA) states that if a user does NOT agree with the agreement, they can contact their manufacturer for a refund. That refund comes from the maker of your computer (Dell, Acer, HP etc) NOT from Microsoft. Naturally, vendors are very hesitent to refund anything. They payed for the lisence once, and now they have to pay again, Either way, Microsoft still has sold a lisence. Manufacturers are also hesitant to refund money because the cost of a retail version of windows ($199can for Windows 7 home premium) is far more then what the manufacturer payed for the OEM installation. Because of Microsoft's contract enforced policy, vendors cannot reviel what they pay. The best estimate is somewhere around $60-$80 for windows 7.
(I count myself among the few people who have actually read the entire EULA, in all it's disturbing detail)