The driver installation may not have completed successfully. If you think this may be the case, follow these steps:
1. Keep your device connected
2. From the desktop, 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 your device. Your device driver will re-install and Windows Mobile Device Center will launch.
Additional Information: http://www.microsoft.com/windowsmobile/en-us/help/synchronize/device-center-troubleshooting.mspx