Windows Mobile Device Cannot Connect (or Quickly Disconnect or Drop) and Not Sync with Vista WMDC (ActiveSync)

Whenever user connect a Windows Mobile device to Windows Vista Windows Mobile Device Center (WMDC) via a USB cable, WMDC fails to connect to the Pocket PC (PPC) Phone device, causing synchronization not start or fail. Sometimes, WMDC may tries to connect to mobile device with “Connecting” message for a while, but eventually fails with “Disconnected” message. In some worse case, Windows Vista doesn’t detect any Windows Mobile device been connected, and no response or connect attempt action in WMDC.

In Device Manager, Windows Mobile-based device driver under Portable Devices and Microsoft Mobile Device Remote Adapter local area network connection under Network Adapters appear briefly before missing or disappearing again. Any connection established is terminated, dropped, disconnected, vanished and disappeared within a few seconds. When the connection is not established, user cannot or unable to sync the PC with desktop, and can’t install applications or transfer files. Soft reset or hard reset the device also does not help to perfectly fix the problem.

Microsoft publishes several troubleshooting tips to fix device unable to connec issue. One of the cause appears to be Windows Live OneCare that blocks the device connectivity. To allow the device to connect via Windows Live OneCare, enable (check) the ActiveSync/Windows Mobile Device Center – synchronize my mobile devices with my computer rule in Firewall Connection Tool button (Firewall tab) of Windows Live OneCare settings. Also in Firewall Tab, click on Advanced button and go to Ports and Protocols tab. Add and create a port called Windows Mobile Device Center with TCP Port Range as 5721, For Connections dropdown as Inbound [local ports] and Scope is set to Local network (subnet).

Other possible cause in failure to connect to WMDC is due to driver installation may not have completed successfully. If you think this may be the case, follow these steps:

1. Keep the WM device connected.
2. Go to Start > Start Search.
3. Enter Device Manager or devmgmt.msc to launch the Device Manager window.
4. Look under the Network adapters node for Microsoft Windows Mobile Remote Adapter. If this is not present, skip to step 5. Otherwise, right-click Microsoft Windows Mobile Remote Adapter and choose to Uninstall.
5. Look under the Mobile Devices node for Microsoft USB Sync. If this is not present, skip to step 6. Otherwise, right-click Microsoft USB Sync and choose to Uninstall.
6. Disconnect and reconnect the WM device. The device driver for the PPC Phone will re-install and Windows Mobile Device Center will launch.

If Microsoft resolution doesn’t help, try to disable the Advanced Network Functionality mode on the Windows Mobile device from the USB to PC icon in Connections of Start Menu Settings. After turning off Advanced Network Functionality, the device will be connected via a USB Serial driver, the sync will be done via native Smartphone USB Sync device driver and no LAN network connection is made.

However, the most likely and most possible resolution for dropped connection and not connected problem for Windows Mobile Device Center is related to Windows Media Player process. On connection with a Windows Mobile device, system will launch wmplayer.exe process, even though Windows Media Player is not ran or opened, and user is not syncing any music, song or media files at internal memory storage or SD memory card.

The wmplayer.exe process for unknown reason will terminate the connection, according to experience of a few users. As wmplayer.exe process won’t terminate itself, user have to end and kill the process as fast as possible once the Pocket PC device is connected to computer and wmplayer.exe process service is launched.

To manually terminate the wmplayer.exe, right click on Windows Taskbar and click on Task Manager. Then click on Image Name to sort the list of processes according to name alphabetically. Locate and highlight wmplayer.exe near the bottom of the list, and click on End Process button. After a while, the device will install with correct driver, connect and WMDC will sync. If the device still doesn’t connect and sync, try to disconnect and reconnect the device again, and kill off any wmplayer.exe service that run after connecting as soon as possible.

If system is not responding to or takes no action to detect, install connect any plugged in Windows Mobile device (and of course WMDC no sync action too), it may be causing by existing wmplayer.exe already existed, blocking future sync process. To fix the issue, open Task Manager (taskmgr in Start Search), and search for any wmplayer.exe service that is running, and kill or end all these processes. Re-connect the Windows Mobile device, and Windows Mobile Device Center should connect and sync properly.