If you have installed CRM 2013 for Outlook and then need to go back to CRM 2011 for Outlook, perform these steps:
- Uninstall CRM 2013 for Outlook
- Delete the program folder, the default location is C:\Program Files\Microsoft Dynamics CRM (or C:\Program Files (x86)\Microsoft Dynamics CRM for a 32-bit install on a 64-bit computer).
- Delete the MSCRM registry keys located at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft and HKEY_CURRENT_USER\Software\Microsoft. There might be several keys including MSCRMClient, MSCRMIntegration, MSCRM_Setup and MSCRM.
If you are not confident editing the registry, then don't! If you modify the registry incorrectly you can cause programs to fail requiring a reinstall.