Fix NS_E_WMPIM_DIALUPFAILED 0XC00D1128 error in WMP

What triggers the 0XC00D1128 error

You're sitting there, try to play a URL in Windows Media Player — maybe an internet radio stream or a remote media file — and boom: error 0XC00D1128. The error message says "The attempt to connect to the Internet failed" or sometimes just "Dial-up connection failed" even though you're on a wired or Wi-Fi connection. It happens most often on Windows 7, 8, 10, and even Windows 11 machines that have ever had a modem or a VPN configured. The real kicker: your browser works fine, but WMP just won't play ball.

Root cause in plain English

The culprit here is almost always Windows Media Player's network profile. WMP doesn't use the same internet settings as your browser. It stores its own connection preferences — including dial-up entries, proxy settings, and modem names — in the registry. If the machine ever had a dial-up adapter or a VPN that left a ghost entry, WMP gets stuck trying to dial that dead line instead of using your active connection. It's not a real network issue. It's a stale config that WMP won't let go of.

Another common trigger: third-party software that tampers with WMP's proxy settings. Malware cleaners, old VPN clients, even some printer drivers can leave behind registry keys that point to a proxy that no longer exists. WMP checks that first, fails, and throws 0xC00D1128.

How to fix it — step by step

Blow away WMP's connection preferences in the registry. This is the nuclear option that works 9 times out of 10. Open regedit.exe as Administrator. Navigate to:
```
HKEY_CURRENT_USER\SOFTWARE\Microsoft\MediaPlayer\Preferences
```
Look for any value named ConnectionType or DialUp. Delete them. Don't touch anything else. Close regedit.
Reset WMP's network settings through the UI. Open Windows Media Player. Press Alt to show the menu bar. Go to Tools > Options > Network tab. Under Streaming proxy settings, click Configure for each protocol (RTSP, MMS, HTTP). Set them all to Use browser proxy settings or Auto-detect proxy settings. Do not use "Use proxy settings" with a manual address — that's what's broken.
Kill any lingering dial-up entries. Open Control Panel > Network and Sharing Center > Change adapter settings. Look for any dial-up adapters, VPN connections, or RAS connections. Right-click and delete any that you don't actively use. If you see a "Dial-up Connection" that you never created, delete it. WMP often picks the first one alphabetically.
Flush the WMP cache. Close WMP. Run this in an elevated command prompt:
```
reg delete "HKCU\Software\Microsoft\MediaPlayer\Player" /f
reg delete "HKCU\Software\Microsoft\MediaPlayer\Services" /f
```
This clears the media library cache and any stored connection data. When you restart WMP, it'll rebuild everything fresh. You might lose your playlists, so back them up first if that matters.
Check group policy if you're on a domain. Run gpedit.msc and go to Computer Configuration > Administrative Templates > Windows Components > Windows Media Player > Networking. Look for "Set network connection type". If it's enabled with "Dial-up" forced, that's your problem. Set it to "Not configured" or "LAN". This is rare outside corporate environments, but I've seen it.

Still failing? Try these

If the error persists after steps 1-5, you're dealing with something deeper. Check for malware that hooks WMP's winsock. Run netsh winsock reset in an admin command prompt, then reboot. That cleans up corrupted socket entries that WMP relies on.

Also, if you're running Windows 11 or a later build of Windows 10, WMP might have been replaced by the Media Player Legacy or the new Media Player app from the Store. Those apps don't use the same registry keys. If the error shows up in the modern Media Player app, just uninstall it and use VLC or MPC-HC instead — honestly, they're better anyway.

The ultimate fallback: delete the entire HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer key and start fresh. That nukes everything — playlists, visualizations, skin settings. But it will fix the error. Only do this if you're comfortable losing customizations.

Bottom line: 0xC00D1128 is a ghost from WMP's past modems. Purge the registry entries, force it to use browser settings, and it'll come back to life. If it doesn't, switch to a modern player. WMP is on life support anyway.