Putting old Windows Vista PC on my LAN but protected from Internet


I am working with an old PC running Windows Vista on my home LAN.

I want it to be on my LAN for network sharing but don't want it to access the internet or have anything on the internet be able to access it.

I followed steps in this tutorial and created a Traffic Rule to block the mac address of the network card in the Vista PC.

Will this not only stop outgoing internet access from the PC but also incoming internet to that PC? I'm thinking of viruses etc..



Assuming you have this rule enabled 24/7 it will block everything from the Vista PC that wants to go to the internet.
Incoming traffic mostly is an "answer" to packets that have been sent out by a PC in your LAN.
Since your Vista PC isn't able to send packets into the internet, there will also be no incoming packets.

Additionally, if there are packets incoming which cannot be associated with an already established connection, they'll be destroyed (dropped or rejected).

So to answer your question: If outgoing packets are blocked there should also be no incoming packets