I do something similar. I simply use TCP for all of my home network, but for my file server, it runs IPX only, and my laptop runs both IPX and TCP so it has access to all those sources. It’s not super secure in that configuration alone, but unless somebody knows to load the IPX protocol and passwords, they won’t even know its there. On my system I also control the IPX packet routing so it only goes between two specific physical ports.

I presume this is a peer to peer network.

If you designate folders on pc1 and laptop1 as shared, it permits access to all on the LAN. It is not designed to restrict access.

You indicate you have a wireless router. I presume it is a low end home grade router which does not have virtual LAN (VLAN) capability. You can replace this low end router with one that supports VLAN capability. In this case pc1 and laptop1 would be on one VLAN (e.g. subnet 192.168.1.0/24) and all the other pcs can be on VLAN2 (e.g. subnet 192.168.1.1/24). This requires more sophisticated configuration and set up but it will provide the requested segregation. Most of these routers are commercial grade and find applications in the business world where employees have one VLAN and visitors have another. An Adtran Netvanta 3120 router with an Adtran Netvanta 150 wireless access point (which can be PoE) is pretty nice and will do the job. Expect to pay around $500 for this and take time to properly configure it as it is more sophisticated. 3Com and Cisco also offer similar products at similar costs.

All you have to do is name your network something that the other computers are not and your network will not be seen by them.