Don't know anything about wireless networking, but normal networking requires file and printer sharing setting up on each system to work properly (though mshome should still show the connected computers).if your internet connection is with the main pc, and your laptop can access the internet through it then obviously you have the required link.
when you ran the network setup wizard, did it complete on both systems OK?
if you right click on your network connection (control panel/network connections) and choose properties, you should have in the main panel
Client for Microsoft Networks
File And Printer Sharing for Microsoft Networks
QoS Packet Scheduler
& Internet Protocols (TCP/IP)
on the advanced tab, make sure that Firewall is turned off.