Windows 7 Media Center, not just a DVR, but a hobby too. I've been running it to record and watch HD TV and listen to music for over a year. For TV, the main reason is we were spoiled with the automatic commercial skipping our Replay TV did. For recorded HD, I think the only option is MC.
It has taken a lot of time to make work and keep working. But it is a fun hobby for the dedicated propeller head. Here are (will be) some notes of problems and solutions.
Other problems, somewhat solved:
View scheduled recordings has gotten very slow. Delete History and it is better now, but still too slow.
Duplicate shows keep showing up on laptop. Used to be restarting MC fixed that, but no longer. Change Recorded TV library folder (only one) various ways; no help. Completely delete Recorded TV library entry, close MC, open Media Player and reset it there; wait until all shows found. Open MC and listings are now correct.
TV says "resolution not supported" sometimes when MC is restarted while TV is on. Turn TV off/on to fix
Other problems, not solved:
Resume from sleep or hibernate; HDMI audio via the ATI Radeon card does not work; have to reboot.
Various recordings showing warning icon and "This recording will be deleted on <tomorrow's date>. But disk with the recording directory has lots of free space (180GB). Setting is to retain recordings until space needed.