Sorry...was in a hurry when I was typing that.....
It was a list of things to check on all the systems.... especially the firewall program(s)....they are known to wreak havoc in networking....
Workgroup name needs ot exactly match.... HOME is not equal to HoMe
LAN IP Subnet needs to exactly match...usually this is lesser of an issue because the default of 255.255.255.0 is prety standard.
I would suggest you set up DHCP reservations in the DIR setups.... This is so there is no confusion incase the LAN IP changes if you reboot the router and the systems reconnect out of sequence from how they were before... In a perfect world, the LAN IP changing shouldn't matter, but this being windows, it can easily induce issues....