What's the proper procedure to block all incoming internet access to my home PC?

So, I've got a question here. Maybe someone who is Microsoft certified can give me a straight answer?

Here’s the deal: I want to ensure that I am the only person capable of making software modifications, provided I'm physically sitting at the machine. Basically, only the locally logged-in administrator should have that power. No one else, and absolutely nothing from the internet, should be able to touch it.

The OS is Windows 10 Pro.

Thanks.

The only way to actually block internet access is to physically kill the connection on that machine. Once it hits the network, remote access is wide open and there’s zero way to stop it...

Thanks for the reply, William Richardson12, even if it wasn't what I was looking for. 😢

You should head over to the Network and Sharing Center, jump into your adapter settings, and go ahead and disable the LAN adapter—and you might want to just shut down the WLAN adapter as well to be safe.

Look, first thing you do is set yourself up with a limited user account on the machine, and then you just go into the firewall and block every single incoming connection and unnecessary port you don't actually need

It’s actually pretty straightforward—https://en.wikipedia.org/wiki/Air_gap_(networking). That was my first thought on the matter. I assume that’s where your head was at, too.