Windows can stay on your computer, when you install Mint! It’s handy to turn your computer into a dual boot machine. That way you can choose each time you turn on your computer, what operating system you want to boot: Mint or Windows.

Note: it’s also possible to install Mint within Windows, basically as an application. This is done with an installer called Mint4Win. I advise against this method, because it’s technically inferior to a normal dual boot on a separate partition on the hard disk.

With a Mint4Win installation of Mint, you have lesser performance, dependance on Windows and its bootloader, less reliable file recovery and some security issues. In short: a separate partition for Mint is much better.

Do you already have a Mint4Win installation of Mint? Then remove it first, within Windows, using Windows’ own Add/Remove Software feature.