Don't have a Windows 7 or Windows 8.1 code? You can then restart your PC, boot from the USB stick, and reinstall Windows 8.1. Once downloaded, this tool will allow you to download Windows 8.1 and make a bootable USB stick with it on. This website can sometimes be unresponsive if you use Chrome or Firefox, so if you have trouble, open it up in Microsoft's Edge or Internet Explorer browsers. If you want to downgrade from Windows 10 to Windows 8.1, then you'll need Microsoft's Windows 8.1 Download Tool. Now check out our how to install Windows 7 from a USB key guide. To download the Windows 7 ISO, go to Microsoft's official Download Windows 7 Disc Images (ISO Files) website, enter in your Windows 7 product key, hit the Verify button and download the ISO. ISO files are disc images that can either be burned to a DVD, placed on a USB stick or run natively, as if the disc was inserted into the PC. If you can't find the discs, then don't worry, as Microsoft offers Windows 7 and Windows 8.1 ISO files for legal download.
