For quite a while I thought my cable signal in my apartment was weak, resulting in the signal falloff artifacts — e.g. stuttering, blocks, etc — but as it turns out I tested the video stream from the HDHomerun on a Mac one day and the video was clear and smooth. I then started prying about the Silicon Dust forums and my own Win7 HTPC.

The solution was either one of two variables, but I suggest you address both if you can.

1. Turn off Vista and 7′s network throttling. This doesn’t have a toggle in the control panel or device settings, so you have to RegEdit it of course. Type regedit in the search bar in Windows 7 and right click and click ‘run as administrator.’ Regedit might not show up in the Vista search, in which case you can find it in your C:\Windows\system32\ directory from explorer. Make sure you open it as Administrator though.
2. Click on through to this folder of the registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile (sorry, regedit is about as intuitive as using a garden rake to comb your hair)
3. There will be a registry key called “NetworkThrottlingIndex” — click this and type in FFFFFFFF in the “value data” box (8 F’s). Hexadecimal should remain checked.  Click okay and the key’s data value should show up as “0xffffffff (4294967295)”. In MS-lingo, this apparently means “OFF” so yay!

The second variable depends on your network card drivers. I had Realtek, so I went to realtek’s website, downloaded the latest ethernet drivers, installed them, rebooted, and changed another type of network throttling, called “Interrupt Modulation,” to disabled in the advanced properties of the device’s configuration window in device manager.

After one final reboot, I had perfect video on my HTPC. Wunderbar!