Well most of us may have encountered this error while using Microsoft USB DVD tool. Ever wondered why this error occur and how to fix it? Because Microsoft USB DVD tool works fine ONLY on untouched official ISO files of WIndows 7, Windows 8 or 8.1 versions. So if you select any other modified ISO or customized ISO images then this error pops up that “The selected file is not a valid ISO file. Please select a valid ISO file and try again.
How To Fix Selected File Is Not A Valid Iso File Error
Well there is very easy alternative for this. Just download the Universal USB Installer from below button and Install it. This is working perfectly fine for all sort of Windows ISO including untouched and modified/customized.
Once you install it, Open the tool and from drop down you can select Windows 7 Installer or Windows 8 Installer. Depending upon your need. If you want to install windows 8.1 still you can select windows 8 Installer option it will work fine. I recently used this tool to successfully installed Windows 8.1 Pro.