[ Thanks to linuxaria for this link.
]
“Operating system not pay $ 400
“The operating system is the set of programs responsible for the
management and control of basic computer operations. A computer to
function, it needs an operating system (there are several: Windows,
Linux, Mac, etc. ..). If you take away the operating system, the
computer serves only as an ornament. The most common is Windows and
we have two options: buy or illegally copied (pirated). Windows
Vista Prices range from $ 299 to $ 599, depending on version
(Microsoft Official List).”