If you need to reload your computer, but you’ve lost your Windows Installation Media, you will need to download a new ISO image to create re-install media. Microsoft provides official ISO images for the Windows operating system, but in some cases (Windows 7 and 8.1) you will need your product key to initiate the download.
Below is a table with the download links for each operating system direct from Microsoft. I have also included links to purchase the software in case you do not have a valid product key.
 | Windows 7 | Download | Purchase N/A |
 | Windows 8.1 | Download | Purchase (Physical Only) |
 | Windows 10 | Download | Purchase (Download – Pro) Purchase (Download – Home) |
