Apologies if this is obvious, but Roon Server is headless, so when you launch it you’re just going to get a Roon icon in the task bar. You’ll need to install Roon on any device you want to configure or use Roon Server from, including the Windows 7 machine.
If you checked Task Manager and Roon is definitely not running, let me or someone from @Support know, and we’ll take a look.