Fix NS_E_UDP_DISABLED (0XC00D00D1) in Windows Media Player

Cause #1: Windows Firewall is blocking UDP traffic

Most of the time, NS_E_UDP_DISABLED shows up because Windows Firewall (or a third-party firewall like Norton or McAfee) is blocking the UDP ports that Windows Media Player uses for streaming. The error often appears when you try to play a network stream or a media file from another computer on your LAN.

Here's the fix that works in 9 out of 10 cases:

1. Press Windows key, type Windows Defender Firewall, and hit Enter.
2. Click Allow an app or feature through Windows Defender Firewall (on the left side).
3. Click the Change settings button. You'll see a User Account Control prompt—click Yes.
4. Scroll down and find Windows Media Player. If it's not listed, click Allow another app... and browse to C:\Program Files\Windows Media Player\wmplayer.exe.
5. Check both Private and Public boxes next to Windows Media Player.
6. Click OK.

After clicking OK, you should see the list update. Now try playing the stream again. If it still fails, move to the next cause.

Real-world trigger: You're trying to watch a live stream from a local server using a URL like http://192.168.1.10:8080 and Windows Media Player throws the error right away.

Cause #2: Windows Media Player network settings have UDP unchecked

Windows Media Player has its own network settings that let you choose which protocols to use for receiving streams. If UDP got unchecked (sometimes by accident, sometimes by a previous optimization guide), you'll see this error.

Here's how to check and fix that:

1. Open Windows Media Player.
2. Press Alt to show the menu bar (if it's hidden).
3. Click Tools > Options.
4. Go to the Network tab.
5. Under Streaming protocols, you'll see three checkboxes: RTSP/TCP, RTSP/UDP, and HTTP. Make sure RTSP/UDP is checked.
6. Also look at the UDP port box. It should be set to a number between 1025 and 65535. The default is often empty, which means Windows picks a random port. That's fine, but if you see a specific port listed and it's being used by something else, change it (e.g., 5000).
7. Click Apply then OK.

After applying, close and reopen Windows Media Player. Try the stream again. If you still get the error, one more possibility exists.

Note: If you're using Windows 11, the menu bar might not appear with Alt. You can right-click the title bar and select Tools from the dropdown. Or just use the registry method below.

Cause #3: Registry shows UDP disabled (or a policy tweak turned it off)

Sometimes the fix isn't in the UI. The real culprit could be a registry entry that overrides the network settings. This happens after some registry cleaners or manual tweaks for performance disable UDP permanently.

Here's the registry path to check:

HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Preferences\IncomingPackets

But honestly, the more reliable registry location is under the network settings:

HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\Network

Look for a DWORD value named UDPPorts or DisableUDP. If you see DisableUDP set to 1, that's your problem.

Steps to fix it:

1. Press Windows key + R, type regedit, and press Enter.
2. Back up the registry first: click File > Export, name it mediaplayer-backup.reg, and save it somewhere safe.
3. Go to HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\Network.
4. If you see DisableUDP on the right, double-click it, change the value from 1 to 0, and click OK.
5. If there's no DisableUDP, right-click in the empty area and create a new DWORD (32-bit) named DisableUDP. Set it to 0.
6. Close regedit and restart your computer.

After the restart, test Windows Media Player. If the registry key wasn't there, moving on to the next cause is pointless because this is the last common one.

What if none of those worked? (Quick check)

If you're still seeing the error, check that no third-party VPN or proxy is interfering. Some VPNs disable UDP for some reason that I can't figure out—they just do. Temporarily disconnect your VPN and test. I've seen this happen with NordVPN and ExpressVPN specifically.

Also, if you're on a corporate network, group policy might enforce UDP off. You'd need to talk to your IT admin. Don't try to override that—it'll just come back.

Quick-reference summary table

That covers all the common fixes. Try them in order, and you'll likely solve it within five minutes. If not, you're dealing with something specific to your setup—maybe a router that blocks multicast UDP. But that's a whole other article.