OK, I followed your steps and it seems to have helped. I did finally get my comps connected.

However I think I have an issue with my second Ethernet connection on my PC Mobo, and that was probably making it harder to get this working.
I have an Abit IP35Pro with 2 ethernet connections. If I use the bottom one I can connect to internet or laptop, if I use the top one I always get 'cable is not connected or broken'.

So it looks like I have to disconnect my modem to connect to Home group.

But at least it works, thanks!