The shortest and simplest way :
Fix for the error :
“The selected file is not a valid ISO file. Please select a valid ISO file and try again.”
is as follows :
- Open your .iso file in Power-ISO(full version if .iso > 300 MB)
- Go to File–>Image properties
- Check UDF
- Press ok
- Save your file
Now use the Windows 7 USB/DVD tool!!
No need to open command prompt at all .
Other method :
http://www.intowindows.com/how-to-create-bootable-windows-7-usb-to-install-windows-7-from-usb-flash-drive-using-windows-7-dvdusb-tool/ [However this above method didn’t work out well using virtual drives (win-7 .iso mounted on Power-ISO). ]