Situation: You wish to schedule Norton AntiVirus (retail versions) to run scheduled scans when a user is not logged in under Windows NT/2000/XP.

Background: You schedule a Full System scan with Norton AntiVirus, and your computer is on but there is no user logged on. You check the Norton AntiVirus and scheduler logs and it appears that the task was not run. There can be several causes for the scan not running.

• Incorrect password used to set up the scan in MS Task Scheduler
• Windows 2000 Home and Windows XP Home do not require a user to set a password, but MS Task Scheduler does require a password to run tasks.
• the /noresults switch was not used in the command line parameters

Below I have listed two solutions to have the scheduled tasks run regardless if a user is logged on or not.

Note: Scheduling a scan with a regular user account is not recommended. On Windows NT/2000/XP using NTFS file system (which is the default files system for these operating systems), a regular user may not have sufficient rights to access all files on the system. Please see the text below for more details.

Task Scheduler: The Task Scheduler first made its appearance with Microsoft Internet Explorer, and was an enhanced scheduler that soon replaced the AT Scheduler. To use Task Scheduler to schedule a program, you need to create the event and use the local administrator account credentials in the ?Run As? box. By default the Task Scheduler will use the currently logged on user. A regular user account will not work since it will have limited rights on the system. The Administrator on the other hand, has full access to all resources on the system.

The following Microsoft Knowledgebase articles describe the steps necessary to schedule events with the Task Scheduler under Windows NT/2000/XP.

• HOW TO: Schedule Tasks in Windows XP
  http://support.microsoft.com/default.aspx?scid=kb;en-us;308569
• How to Schedule a Program Using Task Scheduler
  http://support.microsoft.com/default.aspx?scid=kb;EN-US;178706
• Cannot Configure Scheduled Tasks to Use System Account
  http://support.microsoft.com/default.aspx?scid=kb;en-us;223375

AT Scheduler: The AT Scheduler is the ?Original? Scheduler that came with Windows NT and still remains for backward compatibility in Windows 2000 and Windows XP. The AT Scheduler service runs under the System Account. The System account is a ?Super User? on that machine. It cannot access any network resources, but it has full access to all resources on the local machine. Using the AT Scheduler is the method I recommend in scheduling such tasks that require full access to the system. This will also minimize the exposure of the ?All Powerful? Administrator account. To use the AT Scheduler you must be logged in as Administrator or equivalent to schedule the event.

The following Microsoft Knowledgebase articles describe the use of the AT command.

• HOW TO: Use the AT Command to Schedule Tasks

  http://support.microsoft.com/default.aspx?scid=kb;en-us;313565

• System and User Account Difference with AT Command

  http://support.microsoft.com/default.aspx?scid=kb;EN-US;158825

Note: For those who have NT Resource Kit, there is a tool called WinAT. This is a GUI version of the AT command, and makes scheduling a little bit easier.

Putting It All Together: Now that we have the information necessary to schedule the scan to they run, we need the final and most important piece of the puzzle, the correct Command Line parameters for Norton AntiVirus.

• Norton AntiVirus 2001, 2002, 2003, 2004, 2005, 2006 (including Pro Versions)

  "C:\Program Files\Norton AntiVirus\Navw32.exe" /L /noresults

• Norton System Works 2001, 2002, 2003, 2004, 2005, 2006, 2007 (include Pro Versions)

  "C:\Program Files\Norton SystemWorks\Norton AntiVirus\Navw32.exe" /L /noresults
  

• Norton AntiVirus 2007
  Please see the Symantec Knowledgebase article "Scheduling a recurring full system scan in Norton AntiVirus 2007"

Note: Make sure that the switches are outside of the quotes, as displayed above.

The key parameter is the /noresults switch. This switch tells Norton AntiVirus to do the scan but do not display the results to the screen. The /L switch tells Norton AntiVirus to scan all local drives. In our testing we found that if we did not used the /noresults switch the scan would start but would never complete. Here is usage syntax for Norton AntiVirus:

NAVW32 [path name] [options]

Note: [path name] includes the location of the drive, folder, or file that you want to scan (for example: c: or C:\Program Files\Adobe or C:\Windows). [options] can be any of the command-line options listed in the Command line scan options section.

Command line scan options:

[path name]   Any drive, folder, file, or combination of these is scanned. If you want to scan a combination of items, use a space to separate the items. You can use wild cards when specifying path names for a group of files (for example, NAVW32 A: C:\MYDIR\*.EXE).