Problems sharing files on small home network - help please?

Archived from groups: microsoft.public.windowsxp.basics (More info?)

Hi Group,
I have four XP (3xHE and one Pro) machines connected to a router/hub thru
which they have dsl internet access.
That all works fine.
I have been trying to set up a small home network (simplest possible) so
that each machine can see the shared files on the other machines.
But I am getting inconsistent results.
One machine (XP HE + SP2) can neither see nor be seen by the other three.
It shows the workgroup name under network places but when I poke the name, I
get the red box saying I don't have permissions etc.
I have double checked that the workgroup name is the same on all machines.
I have tried setting up a completely new workgroup name on all 4 machines
using the wizard.
File & print sharing is enabled on all machines.
The whole process appears to be very simple, hence my frustration that it
doesn't work first off.
For "connection method" in the wizard I choose "other" and then "this
computer connects thru a hub" etc etc

First question please:
If I set up a second workgroup, how do I remove the original one?
Both workgroup names now appear in Network Places.
I would like to clean the slate on all machines and start again.
Damn, this cannot be complicated. I must be doing something dumb!!

Suggestions/ideas much appreciated.

Ger