What is ISO file, where did you get it, what program operates or processes it?

[cLitfin]

Windows 10 upgrade, creating bootable USB drive.

 

[Dvx67]

ISO = disc image file. You download it, then use your DVD (or other) burning software to create a disc with it.

You can download the ISO file from Microsoft. I downloaded the flash drive version because it's easier I think.

 

[Bosh_60]

I downloaded the windows 10 64bit (http://fileforum.betanews.com/detail/Microsoft-Windows-10-64bit/1412182607/2) and created an ISO file and saved to desktop. Then use windows 7 USB/DVD (http://download.cnet.com/Windows-7-USB-DVD-Download-Tool/3000-18513_4-10972600.html) to create a bootable disk. I could not get the BIOS to recognize USB boot therefore DVD was used just as in all previous windows releases. Although the windows 7 USB/DVD says "7" it works well with any ISO file to create bootable media and just as important it is very easy to use.

edit: this is to do a clean install. you must first upgrade (using same windows 10 download but don't create ISO file) to windows 10 in order to use this method for clean install. at screens where it ask for product key just skip. If it asks again, keep skipping, it will eventually accept continue installation.