Links to full articles regarding these fixes are below in Related Pages.
Problem: Device Manager only shows the mobile device as Microsoft Windows Mobile Remote Adapter (or Microsoft USB Sync) but not as a Portable Device, so Windows Mobile Device Center will not show the device as connected.
Media Feature Pack: Download all of these, and install any that will, in this order:
1. (v1503) https://www.microsoft.com/en-us/download/details.aspx?id=48231
2. (v1511) https://www.microsoft.com/en-us/download/details.aspx?id=49919
3. (v1607) https://www.microsoft.com/en-us/download/details.aspx?id=53356
4. (v1703) https://support.microsoft.com/en-us/help/4016817/media-feature-pack-for-n-edition-of-windows-10-version-1703-april-2017
5. (v1709) https://www.microsoft.com/en-us/software-download/mediafeaturepack
Uninstall and reinstall WMDC.
For Windows 10 v1709, use the workaround in the DLL article linked below.
Set this to run (for all users) in Compatibility mode for Vista: C:\Windows\WindowsMobile\wmdc.exe
Download WMDC-Helper.exe and Run As Administrator.
Reboot the PC.
Hardware resets, including Warm Boot and Clean Boot may be necessary at this point.
Problem: WMDC will not run on Windows 10 Creators Update (v1703) or Fall Creators Update (v1709):
Run Command Prompt as an administrator, then run these commands:
REG ADD HKLM\SYSTEM\CurrentControlSet\Services\RapiMgr /v SvcHostSplitDisable /t REG_DWORD /d 1 /f
REG ADD HKLM\SYSTEM\CurrentControlSet\Services\WcesComm /v SvcHostSplitDisable /t REG_DWORD /d 1 /f
Services.msc, for both of the following, set the Log On tab to Local System Account, then start the service:
Windows Mobile-2003-based device connectivity
Windows mobile-based device connectivity
If wmdc.exe is running in Task Manager, end task on it, then relaunch WMDC from the Start Menu.
Note: It may be necessary to reapply all or portions of this fix after rebooting the PC.