To dual boot a computer means to run two or more operating systems side-by-side on the same machine. For example, some people run some version of Windows alongside another operating system such as Linux. This gives them access to all the features of both systems. Others run two versions of Windows alongside one another. Dual booting adds a level of complexity to your computer, so it's only worth doing if you have a real need for it and you have a fair amout of computer knowledge.
