Brett928S2 :
Hi
And a small tip from someone who has done lots of networking.....
Every alteration in any network... NEEDS A REBOOT...
All the best Brett
Change of workgroup/domain membership yes, changes to IP configuration etc can be done without requiring reboots.
To the OP - The firewall on the Cisco/Linksys operates between the LAN and the WAN(Internet) side of the router, it shouldn't be filtering any traffic on the LAN side at all.
Are you able to verify basic connectivity between the 2 machines using ping etc? No point in setting up anything new until you can verify that.
Personally I would remove Zonealarm (unless you require the ability to reactively block at the application level) and ensure both machines have their Windows Firewalls set to the Home Zone.
Also have you disabled IPv6 on your network cards, Windows Homegroup requires IPv6 to function.
After quite a bit of searching I can't find a definitive answer as to whether your E2000 is IPv6 capable, so it could well be that causing the issue (or at least the homegroup issue).
I don't see the necessity to create a homegroup on each PC, I would create the homegroup on the Desktop, make a note of the password that is generated and then go to the homegroup settings on the laptop which should detect (assuming connectivity issues have been solved) the newly created homegroup and prompt you to join.