According to a calculation done by the Software Freedom Law Center (SFLA), users of Microsoft Windows are paying as much as $21.50 more for each copy of the operating system they buy, thanks to the so-called “patent tax” that Microsoft is forced to pay to various companies that hold software patents.
Since these “taxes” appear to be required, you can bet all versions of Windows would be cheaper if this didn’t exist. The same goes for OEM PC’s.. the tax would no doubt be included there as well.
Source: Ars Technica