Can you play the avi you put on your HTPC in Media Center on your "Main" PC?
Will your movies on "Main" PC play in the "Videos" Library in Media center on HTPC?
Can you play your Music files from "Main" PC in Media center on HTPC?
I have not played around with homegroups yet - I have all of my machines on a home network as they were when everything was xp.
I suggest setting up your machines on a home Network first - Manually- to make sure they are all "seeing each other" completely. (I know windows 7 automatically networks windows 7 machines together, but if you add a NAS device or an xp machine to your network you will have to do this anyway) Then you can rule out any basic setup or configuration problems. this should not affect your Homegroup settings.
For anyone who doesn't know how to do this:
1.Right click "computer"
2.Select "properties"
3.Select "Change settings" in the name, domain and network section
4.Create a workgroup called "test" (or what ever). After it welcomes you to the test workgroup, reboot. Do this on both machines
5.Go to where your movies are stored on "Main" PC and right click that folder and select "Sharing". Set folder to be shared on the network
6.Now go to HTPC fire up Media Center and add that folder to your Movie Library - even if it says it's there - uncheck it and recheck it and save
see what happens - if it doesn't work in "movies" set the folder up in "videos" just for grins
and try again
stranger things have been known to happen. This
will play your files in media center... and rule out configuration problems.
Once you have that working then you can tweak your homegroup and see what it will do.
Let me know if this helps
