Performing a full system scan means checking each and every item on your computer (memory, disks, mail, etc), which could contain viruses. Follow these steps to perform the scan:
1. From the program window, select the Full Scan option in the Control panel.
2. Select the Scan all system option from the On-demand scans section. This will display all the items that will be scanned.
3. Select the Scan option in the Scan jobs panel. You can also right-click on the Scan all system option and then select the Scan option.
For further information, consult the How to perform a scan (on-demand / scheduled) section in this Help.