From the Start menu, select Programs or All Programs, then Symantec Client Security or Symantec/Norton AntiVirus Corporate Edition, and then Symantec AntiVirus Client or Symantec/Norton AntiVirus Corporate Edition. Alternatively, in the system tray portion of the Taskbar (typically on the lower right of your screen), right-click the Symantec/Norton AntiVirus icon (which looks like a shield) and select Open Symantec/Norton AntiVirus... .
From the Scan menu, select either Scan Computer or Custom Scan.
Select the appropriate drives, mapped drives, and click Scan.