We recommend that you enter the date of your last service pack or installation in order to get the most complete set of updated definitions.
The update will be performed behind the scenes; you will not see a progress bar or receive any sort of confirmation when the update is complete. Instead, simply close the dialog box after you have clicked Go.
Note: If you have customized your field definitions and prefer them not to be changed when this update is performed, you can lock the definitions. Locked definitions will not be updated during this process.