Fix NS_E_PDA_DEVICE_NOT_RESPONDING (0XC00D123A) – WMP Sync Error

You plug in your MP3 player or phone, fire up Windows Media Player 12, and instead of seeing your music library you get that red bar: NS_E_PDA_DEVICE_NOT_RESPONDING (0XC00D123A). The device shows up in Windows Explorer but WMP acts like it's dead. I've seen this most often with older Zunes, SanDisk Sansas, and Android phones on Windows 7 through 10. The thing is — the device is responding to the OS. It's WMP's sync engine that's stuck.

Why this happens

The culprit here is almost always the Media Transfer Protocol (MTP) driver stack. WMP uses MTP to talk to portable devices, not the old mass storage class that shows up as a drive letter. When that driver gets corrupted, or the Portable Device Enumerator service (WPD) hangs, WMP can't initiate the sync session. A second common cause: the device itself has a stale sync partner list or a corrupted media database file.

Don't bother with the Windows Media Player troubleshooter — it rarely helps. Let's fix it properly.

Restart the WPD services – Open an admin Command Prompt (right-click, Run as Administrator) and run these in order:
```
net stop WPDBusEnum
net start WPDBusEnum
```
Then restart Windows Media Player and see if the device shows up. This clears about 40% of cases.
Reinstall the MTP driver – Open Device Manager. Find your portable device under "Portable Devices" or "Other devices" (may show as yellow bang). Right-click it → Uninstall device (check "Delete driver software" if prompted). Then unplug the device, wait 10 seconds, plug it back in. Windows will reinstall the MTP driver fresh. If it doesn't pick it up, right-click any device in Device Manager → Scan for hardware changes.
Clear the device's sync database – This step fixes the "stale sync partner" issue. On the device itself (if it's an Android phone or a media player with file access), go to its internal storage and delete these files if they exist:
- \WMPInfo.xml
- \WMPOldInfo.xml
- \WMPAlbumArt\ (entire folder)
On a Zune or older device, you may need to factory reset the sync settings from the device's menu — look for "Reset Sync Partners" or "Clear Device Database".
Check for MTP conflicts with other software – Some programs like iTunes, Samsung Kies, or old Nero versions hijack the MTP stack. Uninstall the one you're not using. If you have Windows Media Player 11 and 12 both installed (common on Vista), uninstall 11.
Manually re-register the WMP sync DLLs – If steps 1-4 fail, run these commands in an admin prompt:
```
regsvr32.exe /u wmp.dll
regsvr32.exe wmp.dll
regsvr32.exe /u wmpnssci.dll
regsvr32.exe wmpnssci.dll
```
Then reboot.
Switch to a different USB port – specifically a USB 2.0 port – I've seen plenty of cases where a USB 3.0 controller's timing quirks break MTP handshakes. Plug into a black USB port (2.0) on the back of the PC if possible. Also try a different cable — some cheap cables only do charge, not data.

If it still fails

Check if the device works on another PC. If it does, the problem is on your machine — try a System Restore to a point before this started. If it fails on every PC, the device's firmware may need updating or its storage is corrupt. For Android devices, enable "Developer options" and set USB configuration to "MTP" explicitly. For Windows 10, make sure you don't have "Allow Windows to turn off this device to save power" checked on the USB Root Hub in Device Manager (power management tab).

One last thing: if you're on Windows 10 version 1809 or later, Microsoft changed how WMP handles MTP devices. You might need to run the Windows Media Player Setup from the Features menu (Turn Windows features on/off) to reinstall Media Features completely. That's rare but I've seen it twice in the last year.