When you try to sync Windows Mobile Device Center with a 64-bit installation of either Microsoft Outlook 2010 and Microsoft Outlook 2013 or with a Click-to-Run installation of Outlook 2010, you may receive the following error message:
Either there is no default mail client or the current mail client cannot fulfill the messaging request. Please run Microsoft Outlook and set it as the default mail client
However, Windows Mobile Device Center may sync correctly with a 32-bit installation of Outlook 2010 that uses a standard MSI installation. Additionally, Windows Mobile Device Center may sync correctly with 32-bit installations of Outlook 2013.
If a sync partnership already exists and you install an unsupported version of Outlook 2010 or Outlook 2013, Outlook contacts, email and calendar items will be removed from the Windows Mobile-based device during the first sync time. When this happens you can recover the items from your Windows Mobile-based device by installing a supported version of Outlook 2010 and 2013 and using the sync functionality to recover the items.
There are no plans to update Windows Mobile Device Center to improve compatibility with Outlook 2010 and later.
Mail, contacts, calendar and tasks can still be synced over the air with a Microsoft Exchange server running Exchange Active Sync. Windows Phone can also sync over the air with Outlook.com, Gmail, Yahoo mail and others. Windows Mobile Device Center can still be used to sync non-Outlook data from the computer to a Windows Mobile-based device even if running unsupported versions of Outlook.
If you want to sync a Windows Mobile-based device with Outlook 2010, you can use a 32-bit version of Outlook 2010 that uses a standard MSI installation. Additionally, Windows Mobile Device Center may sync correctly with 32-bit installations of Outlook 2013.