NS_E_REG_FLUSH_FAILURE (0XC00D2798) — Windows Media Center/PVR fix

When does this error show up?

You're watching live TV through Windows Media Center, or you've got a scheduled recording set up. Suddenly, the screen goes black. Or the recording just stops mid-show. When you check the error log, there it is: NS_E_REG_FLUSH_FAILURE (0XC00D2798). I had a client last month whose entire PVR setup died right before the Super Bowl. He had a Hauppauge WinTV card and Windows 7 Media Center. Same story: recording would start, run for 10 minutes, then bomb out with this code.

What's actually going on?

Windows Media Center uses the registry to store metadata about recordings — title, channel, timestamps, series info. When it tries to write this data to the registry, something blocks the write. Then Windows can't commit (flush) those changes from memory to the registry file on disk. The error code 0XC00D2798 literally means "registry flush failed."

Three things usually cause this:

• Registry corruption — a bad shutdown or crash left the registry in a state where it won't accept writes.
• Permission issues — the Media Center process (ehrecvr.exe or ehshell.exe) doesn't have write access to the relevant registry keys.
• Antivirus or security software — some overzealous AV tools lock the registry hive, preventing any writes. I've seen Norton and McAfee do this.

Fix it: Step by step

Skip reinstalling Windows. That's a last resort. Here's what actually works.

Step 1: Stop all Media Center services

Open an admin Command Prompt (right-click the Start button, choose "Command Prompt (Admin)"). Run these commands one at a time:

net stop ehrecvr
ehentry
net stop ehshell
net stop ehome

This kills the PVR engine, the Media Center shell, and the entire eHome service group. If any of these are already stopped, ignore the error — just move on.

Step 2: Clean up the registry keys that cause the flush failure

Press Win+R, type regedit, hit Enter. Navigate to:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Media Center

Look for a subkey called MediaCenterRecorder or TVRecording. If you see either:

• Right-click it and select Export to back it up (save to Desktop as a backup).
• Then right-click again and choose Delete.

Also check here:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Service\Recording

Same thing — export first, then delete the entire Recording key if it exists.

Step 3: Fix permissions on the registry hive

Now go to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters

Right-click the PrefetchParameters key, choose Permissions. Make sure SYSTEM has Full Control. If not, add it. This is the key that sometimes gets locked after a crash. Don't ask me why Microsoft chose this key — it's just what the kernel uses to flush registry writes.

Step 4: Rebuild Media Center's database

Open Media Center. Go to Tasks > Settings > TV > Setup TV Signal. It'll ask you to reconfigure your tuner. This rebuilds the recording database from scratch. It takes about 5 minutes. Accept the license agreements, let it scan channels again.

Step 5: Restart the services

Back in your admin Command Prompt, run:

net start ehrecvr
ehentry
net start ehshell
net start ehome

Or just restart Windows. I usually restart — it's faster than trying to start them in the right order manually.

Still failing? Check these

If the error comes back, you've got one of two problems:

• Antivirus interference: Temporarily disable your AV (not just real-time protection — fully disable it). Try a test recording. If it works, you need to add an exclusion for C:\Program Files\Windows Media Center and the ehrecvr.exe process in your AV settings.
• Corrupt Media Center database: This is rarer but happens. Open Media Center, go to Tasks > Settings > General > Media Center Setup > Reset to Default. This nukes your recording schedule and guide data, but it fixes a corrupted database 9 times out of 10.

I've seen this error on Windows 7, Windows 8, and Windows 8.1. Windows 10 killed Media Center, so you're stuck on those older OS versions. If none of the above works, you might be looking at a hardware issue — bad RAM that corrupts registry writes. Run MemTest86 overnight to rule that out.