If it's Windows 10 we can make some USB Bootable Windows 10 install media on a good PC. Read https://www.microsoft.com/en-us/software-download/windows10 on how to get and use the media creation tool to make a bootable USB stick.

That said and I can't guess why but a few people report back they downloads the .ISO which I've never had happen with this tool.

Now that we have our USB Bootable Windows 10 stick we can start from scratch and then go get drivers and what not for this unknown PC.