There are two HdHomeRun quatro Tunners on the same network along with the old and new machines. There is a Linksys extender on the network too.
Machine old
Windows 7 ultimate sp1 64bit 6 gig ram with some unmatched ram brands - that never caused a problem... (?before?)
Ran/runs great for years but subsequent to Add Additional Quatro, Setup Data Not Found back in September when I also upgraded to a 2 gig drive using macrium reflect and removed a couple tuner cards, it's had an, all to often, abnormal termination (abend) of the app / OS without a blue screen of death. I also watch Netflix, hulu etc on this same machine during this streaming the machine never abends. When a WMC playback abends I then successfully watch the show with windows media player. I'm 97% sure that when I watch some shows with the extender the extender abends but the WMC server doesn't crash. Kinda weird ehh? I did order up some new matched vendor RAM for this old machine that has been adequate so I'm hoping to use it as I could use the newer machine for other projects... Stability of my WMC is paramount!

Machine new
Windows 7 ultimate sp1 64bit
Newer i5 cpu with 6 gig of matched ram.
installed from win 7 usb .iso this morning. Installed updates.
- Jeff