Windows 7 with Service Pack 1 (SP1)
These ISO files are hosted by Microsoft’s partner, Digital River. I’ve had some issues downloading from this site, so don’t despair if it’s balky for you.
Note that each version is multi-language. So you can choose at Setup.
Use Microsoft’s Create installation media for Windows 8.1 site to create a Windows Setup USB flash drive or download the ISO file. Here, too, the tool is multi-language, though the ISO you download will be locale-specific, so make the right choices up-front.