Bitcoin Node on an old business server

I inherited 2 very nice business servers from my boss.

1 is setup (actually both) have been setup with Windows 10 interface, but he told me one of them could be used with any OS.

1 I will use as my own personal server, but the other one is going to be a Bitcoin node.

The question is: Which OS should I us?

Start9 OS is attractive, seems easy enough to operate and has access to their Start9 apps

Not sure about other OS and I am a complete newbie with anything but Windows.

I'm all ears!!!