Another great article from the folks at HowtoGeek.com. The article mentions Win8 but also applies to Win7.
How to Dual Boot Windows 8 and Linux Mint on the Same PC
If you’re a serious operating system geek, you might want to test out both Windows 8 and Linux Mint. Here’s how to get the best of both by dual-booting Linux Mint with your Windows 8 installation.
Before we start there is a couple of things that you are going to need:
- 10GB of free space on your drive
- The Linux Mint DVD, from here (x86) or here (x64), burnt to a DVD.
- About 30 Minutes of free time
The DVD should automatically boot into its Live mode, however if you bump a key and are prompted simply choose to start it.
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Once you have clicked on the continue button you will now have to pick a place to install Mint, scroll down until you see a partition called “free space”.
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Double click on it to bring up the format menu, here accept all the defaults except for the mount point, where you should enter a single forward slash, then click ok.
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Now you can click on the install now button.
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A very nice touch to the installation process is that it starts asking for a few configuration settings while the OS is busy installing.
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You will need to reboot your PC when the installation is finished, as you can see we can now easily choose our OS at startup.
Note: Grub picks up our Windows 8 installation, the entry at the bottom, as Windows Recovery Environment, this is actually your Windows 8 installation and the display name can easily be changed by selecting it from the menu and hitting the “e” key, this is mainly for advanced users.
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Your default OS will now be Linux Mint, but you always have the choice of switching back to Windows 8 from the Grub boot menu at any time.
Source: http://www.howtogeek.com/99060/how-to-dual-boot-windows-8-and-linux-mint-on-the-same-pc/