Ok, here is an event that happened today. Unfortunately I did not thuroughly test everything after this occured but I plan to look into it further.
Here is a little background: I currently have 3 PCs all running Windows 7. I have my main PC that is wired to the network running x86 7057. I have a laptop that was running 7000 and obviously connected wirelessly. I also have an HTPC running x64 7068 that connects wirelessly as well. All of them are part of the same homegroup.
Now, today I was watching a movie with the htpc that was being shared from the laptop. It was only maybe a third of the way through when I had to disconnect my router because I was installing a new one. After I powered off the router and disconneted everything I fully expected the buffer on the movie to run out shortly and it to cut out. However, it did not. In fact it kept playing for well over an hour until the movie was finished. Once the movie stopped, MCE did come back up saying it could not find any shared libraries.
So, my question is, did the HTPC really buffer the whole movie in the short amount of time that I had watched the first part of the movie? Otherwise it would seem that the HTPC and laptop had connected to each other wirelessly to continue playback once the router was removed.
I tried to find more information about this but it was kind of a vague search topic. Maybe I missed this in an article about Windows 7 or homegroups.
Anyway, I just thought it was an odd event and figured someone here would know what was going on. Like I said before, I do plan to try to reproduce this an test further if someone does not have a simple answer.