XP Mode, sharing files on guest machine

Kari, I have done some digging around and found that before an XP computer to be detected and appear on a network map it must have installed LLTD protocal. I do not know yet if I have that or not on XP Mode.

I have also looked into "Homegroup" and found that it only works with other Win 7 computers. Typical !

I am needing to have at this stage in a closed "network group" my Win 7 computer, my XP Mode, my Mac and my HTC Desire mobile phone, with ability to add more on later. However I also need to allow at least 2 other computers to have access to the internet through the same router, while not having access to my own closed network. This may make my needs more clear and I will keep searching for the answers at my end.

I understand from what you say that Homegroup is a Win7 subgroup of the Workgroup. Workgroup is the one that all computers in the Local Area Network are members of. But I cannot see any other computers in my network picture, except the computer I am using at the time to look at it. It is as though all computers exist individually, all connected directly to the router, without seeing any other associated computer. There does not appear to be a Workgroup as such. I am missing something simple I think, but cannot put my finger on it.

On my Win 7 looking up Network Local Area Connection Status it tells me that
IPv6 Connectivity: No network access
I have missed something basic I think

Now you are asking something !? from a newby like me.
Please be patient with me and I will give it a go.

Sorry this is to difficult for me to do in a hurry Kari. While in the process of getting the image I pushed the wrong X in the tpo right hand corner and shutdown XP mode with the forum connection etc etc and it all went belly up. So I will just have to type in the answers for you.

XP Mode: Networking Network Adapter:1 Shared Networking (Nat)

Please note: I did change it to the other choice (Realtek RTL... Family PCI-EGigabit Ethernet NIC (NDIS.2) as you instructed, but I immediately lost internet connection with XP Mode. Local area connection stated limited or no internet connection. When I changed it back it restored the internet access to XP Mode.

No there has been no mention of this until now that I recall.
I will investigate and try it.