After Microsoft Forefront Protection 2010 for SharePoint (FPSP) is installed, updates automatically begin downloading five minutes after your installation is complete. By default, FPSP ensures that you are protected by performing updates every day on an hourly basis. Engine updates and definition updates can be downloaded automatically from the Microsoft HTTP server, or from another SharePoint server running FPSP see Distributing updates by using UNC updating. When FPSP downloads an update, it takes the engine offline (provided it has been enabled for a currently-running scan job), automatically installs the update, and then puts the engine back online. The other engines continue to scan for malware.
It is recommended that you use the default schedule to update scan engines hourly. However, if you so choose, you can create your own schedules for performing updates (see Configuring and scheduling updates). You can also run updates immediately as needed (see Downloading updates immediately). After you have configured your update settings, you can view engine summary information (see Viewing engine summary information).
|An engine update refers to updating to a new version of a scan engine (which replaces the old version), whereas a definition update refers to new definitions being added to an existing scan engine. You should expect to see definition updates occur frequently, but not engine updates. Nevertheless, an update-check for both is done at the frequency and repeat interval that you have specified. If no new files are available, nothing is downloaded for that engine during that update cycle.