(Windows-10-home)2015(version-1511)os-build-10586.36(64-bit) upgraded succesfully, but I need a copy of installation iso file

My HP 2000 notebook pc upgraded to windows 10 home (2015) version 1511 (os build 10586.36) 64-bit (product id 0036-10000-00000-AA788) succesfully (thru inteet) but now I need .net framework 3.5 installed, but to use offline installer, I need a copy of installation iso file. Where can I find one?