I have a ~500gb hard drive that I intend to split 50/50 for Windows 10 and Linux Mint 17. The Windows partition is 232GB and the Linux partition is, at the moment, uncreated. When I run Mint off my pen drive and go to install it, it shows the hard drive as 500gb of 'free space'. I can't install because it will wipe my Windows install.
How can I get the partition to show in Mint?