The proper way of installing a dual boot mode computer running Windows 10 and Linux is the same as in other versions of Windows. You should install Windows 10 first, then install Linux second. That’s the best approach in my opinion. If you do it the other way, you will lose the ability to boot into Linux, because Windows overwrites Grub, the boot loader program used in Linux. You will have to boot your system with a Linux CD, repair Grub and add the Windows instance in Grub. That’s just too much work. Sometimes you don’t have much of choice. Even if Linux is already installed, it’s much easier to blow it up and reinstall.
I’m not sure why it is so difficult to make Windows and Grub to co-exist. Oh, they do work. They work like a charm. The issue surfaces each time there is a new iteration of the latest Windows OS, in this case Windows 7. It blows off the Grub configuration and makes it unusable. It rewrites the Master Boot Record deeming your Grub configuration unusable.
How rude it is for Microsoft to assume that Windows is the only operating system available on a computer. One more thing, if you are going to have a dual boot system, it is advisable to install Windows first. If you install Windows last, it will rewrite the MBR making it impossible for you to get to your Linux distro. It’s not really gone. Windows just screwed up Grub and overwritten the MBR. You have to boot from a Linux CD and restore Grub.
I just wished Windows would behave well and co-exist with Linux. It’s this kind of provocation that alienates Linux users even more.