[2020] Question about ECO

We never supported Windows 7 on Steam and its EoL, we cannot guarantee for it to be working anymore, especially as Unity tends to implement breaking stuff for older OS that they only fix very slowly. Upgrading is recommended in any case, as we only officially support Windows 10.

You actually don't need to buy Windows 10. A Windows 7 Key is still upgradable for free, search around in Google a bit :)