Limited virtual space available for Symantec Protection Engine (symcscan) service, which impacts scanning performance.

On 32-bit editions of Windows, applications have 4 GB of virtual address space available. The virtual address space is divided so that 2 GB is available to the application and the remainder 2 GB is available only to the system. The 4-gigabyte tuning (4 GT or 4 GT RAM tuning) feature, increases the virtual address space that is available to the application up to 3 GB, and reduces the amount available to the system to 1 GB and 2 GB.

To resolve this issue, enable LARGEADDRESSAWARE for 32-bit applications on 64-bit Windows system, by performing the following steps:

1. Open the command prompt with administrator privilege.
2. Take a backup of the original settings as bcdedit > before.log.
3. Run the below commands :
   bcdedit /set IncreaseUserVa 3072
   Run bcdedit before reboot to see if IncreaseUserVa is set to 3072.
4. Reboot the system to bring the change into effect.
5. After rebooting, run "bcdedit" from the command prompt and verify the following values:
   increaseuserva          3072

For more information on 4-Gigabyte Tuning: BCDEdit and Boot.ini, go to https://msdn.microsoft.com/en-us/library/windows/desktop/bb613473(v=vs.85).aspx