UniqueID said:
which other operating systems have you tried?

and what didn't you like about them?
Nothing wrong with apple, linux ect as a home os.
However it doesn't give companies the flexibility, compatibility and cost effectiveness as Windows.
Windows, is all one nice file format, that will run anywhere in the world on everyone elses system, you can use legacy equipment, you can buy equipment from anywhere, rather than paying for an over priced apple box (unless your doing graphics). etc etc etc.
The biggest thing with windows is
ease of use for employees
compatibility world wide with other companies
Compatibility and integration of thousands off diffrent machines.
this then filters down to home users, which can roughly be split into 3 groups
1) casual user who might do some work at home, they already know windows so why learn something else and worry about file formats and compatibility.
2) Gamers, windows is the only option there
3) computer enthusiasts, which i would says still favourers windows but also user various Linux distros and os x