The ISO is the image.
" Copies: To install the software, you may make one copy of the ISO file on a disc, USB flash drive, or other media. After you’ve installed the software and accepted the license terms that accompany the software, those license terms apply to your use of the software. The license terms for Windows 7 permit you to make one copy of the software as a back-up copy for re-installation on the licensed computer. If you do not delete your copy of the ISO file after installing the Windows 7 software, the copy of the ISO file counts as your one back-up copy. If you need to download the software again, you can go to your Download Purchase History in your Microsoft Store account and access the download there." What error message do you get? Do you have a dvd/cd drive? If so try burning the ISO to a disk and installing from that. Did you purchase the download and do you have a valid license key?