Hi, first sorry if my English is not good
I always install windows by this simple way and I have no problem so far. I extract iso file into one of drive with winrar. For windows 7 and 8 run setup.exe in the root drive and follow steps until that step I want select drive. If I want to replace windows, select windows drive and if I want have Dual Boot select other drive. Boot menu automatically is creating and is include two or more windows that I installed. For windows 8.1 and 10 because I can't select drive by run setup.exe in root folder, I run setup.exe into sources folder like you.
Just two issues. One that windows 64 bit can't run into windows 32 bit and two that older version can't install by way of newer version.
But Except two issues for other cases is best.
Now I want to know your Opinion for this.
is this way correct for installing windows?