Turn off firewalls on both.
Make sure both have same workgroup name.
Share at least one folder on each PC.

This should make the two Pcs see each other on the network. It could take up to 45 minutes for them to work. Or they may have problems seeing each other anyway.

You can "force" one to see the other if needed, by using the address bar in Windows Explorer.

Just type the path needed. If computer1 is named frontroom
then type in the address bar
and press ENTER. If the PC is on the network and is not blocked by a firewall, shared folders will show up, even if you can't browse to them.