NS_E_BAD_ADAPTER_NAME (0XC00D00CC) – Adapter Name Invalid Fix

When You'll See This Error

You're trying to stream a video in Windows Media Player or an app that uses DirectShow, and instead of playing, you get something like: "The specified adapter name is invalid (0XC00D00CC)". I see this most often after someone resets their network stack—maybe they ran netsh winsock reset or uninstalled a VPN. The app tries to grab the network adapter by name, but the name it stored doesn't match what's in the system anymore.

Why It Happens

Windows keeps a list of network adapters with GUIDs (like {E846F3B6-4C7A-4A3B-9B4F-3C2A1D3E5F6A}). The app holds onto the old GUID. When you change adapters—switch from Ethernet to Wi-Fi, install a virtual adapter from a VM, or reset network settings—that GUID changes. The app can't find the old one, so it spits out NS_E_BAD_ADAPTER_NAME.

Fix It in 3 Steps

Step 1: Find the Current Adapter Name

Open Command Prompt as admin (right-click Start, pick Command Prompt (Admin) or Windows Terminal (Admin)). Type:

wmic nic get name, index

You'll see a list like:

Index  Name
0      Realtek PCIe GbE Family Controller
1      Microsoft Wi-Fi Direct Virtual Adapter
2      VirtualBox Host-Only Ethernet Adapter

Pick the one you're actively using (usually Index 0 for wired or the wireless one). Note the Index number.

Step 2: Update the Registry

This part is where the magic happens. Press Win + R, type regedit, hit Enter. Go to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Media Foundation

Look for a key called DefaultAdapter on the right side. If it's there, double-click it and set its value to the Index number from Step 1 (e.g., 0). If it's not there, right-click in the right pane, choose New > DWORD (32-bit) Value, name it DefaultAdapter, and set the value to that Index number.

Step 3: Restart the App

Close Windows Media Player or whatever app gave you the error. Reopen it and try streaming again. That's usually it—no reboot needed.

If It Still Fails

Two things to check:

• Make sure the adapter Index is correct. If you have multiple adapters (like from VMware or Hyper-V), the Index might shift. Re-run wmic nic get name, index and confirm the number.
• Check if the app is 32-bit. Some older apps look in a different registry path. If the first fix didn't work, try the same registry change under HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft\Windows Media Foundation.

I've seen this trip up IT folks who forget the WOW6432Node for 32-bit apps. The error code doesn't tell you it's a 32-bit vs 64-bit mismatch, but it's a common culprit.

One Last Workaround

If editing the registry makes you nervous (and I get it—messing with the wrong value can break things), you can try disabling all virtual adapters in Device Manager. Uncheck anything that isn't your physical Ethernet or Wi-Fi adapter. Restart the app. Sometimes that bypasses the whole naming issue because the app just picks the first real adapter it sees.

This error is a small annoyance, but once you know the fix, it takes 30 seconds. Hope this saves you some head-scratching.