Just a must do if using Win(xxx) - Do backup your Master Boot Record.
I've used MBRFix, early on when dual booting Linux with Win and found it worked well.
Very simple to use; just download from a trustwothy source : http://www.softpedia.com/get/System/Hard-Disk-Utils/MBRFix.shtml
Run - in Windows; before installing Linux.
Use command in Pic which creates a .dat file in the root of C:\ - if things go wrong you just delete the Linux partitions from inside of your Win install, and restore it's MBR. For a single Hard Drive, Dual Boot setup, although there are many commands so you may have further options with multi Drive setups.
So important to do this first time when you may be nervous, or unsure, and muck up.