In Windows, Symantec Endpoint Protection uses the following registry key to store information about the last time a virus scan was completed:
64bit operating system:
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Symantec\Symantec Endpoint Protection\CurrentVersion\public-opstate]
32bit operating system:
[HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\Symantec Endpoint Protection\CurrentVersion\public-opstate]
Upon checking registry, above entry may not exist.
This registry entry, along with relevant value, is only created after completing first scan.
Run and complete Active Scan / Full Scan to see the entry being created and populated with date / time value.