Try to determine where that file was downloaded to. Do not be concerned if you do not know
as we will search for it again later in step 12 and 13. The installation ISO file will most
likely be saved to your browser's default download location.
If you are using Firefox then you may see a Downloads Library :
Within Windows 10 Edge you may see :
Regardless how you download the netinstall file you will be able to search for it later.