How many times have you wanted to test another operating system  but you are scared of compromising  the working  of your computer? From this question you already guessed  the functionality of the virtual machine (VM).
The virtual machine is an application installed on your computer that allows you to install an operating system without risk of affecting the operation of your computer. Indeed, it creates a file in a folder that we choose where our operating system will be available.
However, there are various aspects in the use of virtual machine that we have to consider. Although the virtual machine supports an operating system, it needs a computer with high performance to get the best from it, because the virtual machine requires the same resources that normally the installation of the operating system requires.

There are a lot of software for creating virtual machines the most famous are VMware, VirtualBox and Microsoft VirtualPC.
VMware (www.vmware.com) is more complete it is used in the work place and  it  is not free. VMware can emulate Windows, Linux, Sun Solaris and others. The operating system installation is done using a simple wizard and it is intuitive.
Microsoft VirtualPC  (www.microsoft.com/windows/virtual-pc/) is less complete but at least it's free. In this virtual machine we can emulate only Microsoft Windows operating systems but it is a good tool for those who want to test the various Windows systems.
VirtualBox (www.virtualbox.org/) is free for personal use. This virtual machine supports major operating systems Linux, Windows and Solaris as well. The only downside of this emulator is the configuration because it is a bit more complex. However, there are several guides on the official website and forums that make it easy to set up the virtual machine.