Because they have applications that won't run on it.
If that company was Apple or Microsoft, using Linux instead would be a bit bad for business.
Most people do not currently use Linux on their computer at home, so they will be unfamiliar with it. Thus, the employees will need to be taught how to use the new interface and / or software. In a small company, this may be relatively easy, but it will be time-consuming and probably costly to train thousands of employees in a larger company. Also, a few companies may rely on specialized software that has not been ported to Linux, and cannot be run feasibly with Wine.
There are several desktop environments for Linux currently in use. The most popular are GNOME and KDE.
The primary software that they use is in no way compatible with Linux. They do not want to spend any money on retraining/ rehiring IT. They have a deal going with manufacturers and Microsoft. There are many other reasons why a company would opt not to use linux as well as many why they would.
Yes it is possible to do so. Once you have them, at the login screen you should find an option that allows you to choose which desktop environment you want to use.
mint, ubuntu, debian
Red Hat Enterprise Linux is most commonly used for servers, but some high-end workstations often use it as well. The "enterprise" means that this particular Linux distribution is designed primarily for business use. Red Hat (The company.) also has a desktop variant of Red Hat called "Fedora." It is geared for home users, and it is also where some of the more "experimental" desktop technologies come from, such as PulseAudio and systemd.
None. Any distro branded "Mandrake" is long obsolete; the parent company renamed itself to "Mandriva" in 2005.
GNOME is the name of the desktop environment; it isn't any particular location. The GNOME desktop will typically appear once you log in. If you have multiple desktop environments installed, you can typically choose the one you want to use from the Options menu in the login screen.
It's about as easy to use as any Linux distribution. The main point it lacks in is hardware support, which isn't quite as good as Linux's. It uses the KDE desktop, which is also found in many Linux distributions.
Windows, MacOS, and Linux are the most common.
i love linux, but company's people all use windows. so i need use xp