Or, to remove a group, click and drag the group below the header row and then release the mouse button when an X appears.
These screenshots are from Outlook 2013, but the process works identically in 2010 or 2007. Choose "Update All", wait a moment, and you're done. Switch to your contacts view, then go to the "Send/Receive" tab.
From there, right-click any selected contact and choose "Add to Contacts".
However, the user can manually update Outlook contacts, or if there are many differences, the user’s mailbox can be restored.
A programmatic solution is possible, but requires complex data validation to pull the previous values from the Notes field.
However, if contact synchronization is a large issue in your organization, you can disable GAL synchronization for Outlook 2010, either before you deploy Microsoft Office 2010, or when you see potential for this situation occurring.
For the contact corrections Outlook makes during GAL synchronization, and the list of settings that you can configure, review the global address list synchronization section in Determine which features to enable or customize in Outlook 2010.
To disable GAL synchronization by using Group Policy The Block Global Address List synchronization setting is also available in the Office Customization Tool (OCT) under Microsoft Outlook 2010\Outlook Social Connector on the Modify user settings page.
You can configure this setting for a setup customization file (.msp) and then deploy the configuration as part of the Office 2010 setup.
To download the Outlook 2010 template and for more information about other Administrative Template files, see Office 2010 Administrative Template files (ADM, ADMX, ADML) and Office Customization Tool.