Fix NS_E_INSUFFICIENT_BANDWIDTH (0xC00D002C) – Not Enough Bandwidth

Quick Answer

Disable the QoS Packet Scheduler or remove the Group Policy bandwidth limit at Computer Configuration > Administrative Templates > Network > QoS Packet Scheduler > Limit reservable bandwidth — set it to Not Configured or 0%.

What's Actually Happening Here

You're trying to stream a video in Windows Media Player (or an app that uses its stack—like some old Win32 media players or embedded web players) and instead of playing, you get NS_E_INSUFFICIENT_BANDWIDTH (0xC00D002C). The error says “insufficient bandwidth,” but your internet speed test shows 100 Mbps. The real culprit? Windows can reserve up to 20% of your bandwidth for QoS (Quality of Service) by default, and some Group Policies or third-party network managers crank that up or misconfigure it. It's not that your connection is slow—it's that the system artificially restricts how much the streaming app can use.

This pops up most commonly in Windows 10 22H2 and Windows 11 23H2 after an update that resets network policies, or after installing a VPN or gaming optimizer that messes with QoS. I've also seen it on corporate machines where IT pushed a bandwidth-limiting GPO.

Fix Steps

1. Check and disable QoS Packet Scheduler. Right-click your network icon in the system tray > Network & Internet settings > Advanced network settings > More network adapter options. Right-click your active adapter (like Ethernet or Wi-Fi), select Properties, uncheck QoS Packet Scheduler, and hit OK.
2. Open Group Policy Editor (press Win + R, type gpedit.msc). Navigate to Computer Configuration > Administrative Templates > Network > QoS Packet Scheduler. Double-click Limit reservable bandwidth, set it to Enabled, then set Bandwidth limit (%) to 0. Apply and restart.
3. Flush DNS and reset Winsock (this clears leftover QoS policies that cling to the stack). Open Command Prompt as Administrator and run:

   netsh int ip reset
   netsh winsock reset
   ipconfig /flushdns

   Reboot after.
4. Disable Teredo tunneling — this legacy IPv6 transition tech is known to cause bandwidth errors on streaming. In the same Admin CMD, run:

   netsh interface teredo set state disabled

5. Test on a different player — if VLC or MPC-HC plays the same stream fine, the issue is definitely inside Windows Media Player's bandwidth estimation logic, not your network. If it fails everywhere, check your router QoS settings.

Alternative Fixes If the Main One Fails

• Reset Group Policy to defaults: If gpedit.msc isn't available (Windows Home edition), use the Registry Editor: go to HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Psched and delete the NonBestEffortLimit value if it exists. Create it as a DWORD set to 0 if not.
• Disable Large Send Offload (LSO) in the network adapter properties under Advanced. LSO can sometimes overrun media player buffers, which gets misdiagnosed as bandwidth shortage. Set IPv4 and IPv6 LSO to Disabled.
• Switch to a wired connection temporarily — some Wi-Fi drivers report incorrect link speed to Windows, triggering the bandwidth check. If wired fixes it, update your Wi-Fi driver.
• Run the Windows Media Player Network Sharing Service repair: services.msc > find Windows Media Player Network Sharing Service, stop it, set to Manual, restart the player.

Prevention Tip

After fixing, avoid installing network “optimizers” that claim to prioritize gaming or streaming traffic — they often re-enable QoS limits under the hood. Leave Group Policy's bandwidth limit at 0% or Not Configured. If you're on a domain, talk to your IT admin; ask them to exclude your machine from the bandwidth-limiting policy for media apps. And keep Teredo off unless you specifically need it for Xbox DirectPlay or old peer-to-peer games.