On the Engines tab there are displayed names of all the available scanning engines, their versions, the date of antiviral signatures update and its current status (licensed or unlicensed).
On the tab there is a list of engines with defined sequence of using (this sequence is called "the cascade"). The engine at the top is used for virus detection and updating as a first, next as a second and so on. This cascade is possible to change by the arrows by the right side of the list. Besides, every engine has a checkbox near by his name. This checkbox defines if this engine shall be used or not.
Every engine has two checkboxes. These checkboxes are determinig which scanner will be used with this engine, so you can change speed and detection abilities of each antivirus engine. First checkbox sets On-Demand scanner, second checkbox sets On-Access scanner. For example you can set just one engine to work as On-Access scanner engine and all engines to work as On-Demand scanner engines. This will lead to fast On-Access scanning and maximal detection ability of On-Demand scanning.
After selecting a scanning engine, you can use the Configure button to set the URL that updates will be downloaded from. If the update files are available at the given time, the update is performed. If the computer is inactive (shut down) at that moment, the update is performed at the nearest suitable occasion (after the next computer start).
For the administration of servers from which the update packs can be downloaded from, there are Add and Remove buttons.