upgrading to windows 10 frm windows 8 will affect partition

Jul 26 2016 4:46 PM

will upgrading to windows 10 from windows 8.1 using ISO affect other hard disk partitions? will it merge all partitions to a single partitions? actually i need to upgrade my laptop to windows 10 and other partitions contains data which do not want to be lost. please give me the steps. 