How to fix and rebuild corrupted definitions for a Symantec Endpoint Protection 11 or 12.0 client when Symantec Mail Security for Microsoft Exchange is installed on an Exchange 2003 system.
Stop the following services
Symantec Management Client
Symantec Endpoint Protection
Symantec Mail Security for Microsoft Exchange
Navigate to the following location: C:\Program files\common files\Symantec Shared\Virus Defs
Remove the newest numbered folders and any tmp folders.
Navigate to following location: C:\Program files\common files\Symantec Shared\definitions\Antivirus
Remove the virusdefs##### folders but leave the virusdefs folder. WARNING: In the next steps you will edit the Windows registry. Back up the registry before you make any changes to it, because incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the registry keys that are specified. For instructions, see How to back up the Windows registry.
Delete the data from the registry:
Click the Start button and then click Run
Type regedit and click OK
Navigate to: HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\SharedDefs
Delete the following keys:
Start the Symantec Management Client and Symantec Endpoint Protection services.
Allow time for the definitions to rebuild. (This can take up to 10 minutes to accomplish.) Verify the definitions are correct by inspecting "C:\Program Files\Common Files\Symantec Shared\VirusDefs"
Start the Symantec Mail Security for Microsoft Exchange service.
Log into the Symantec Mail Security for Microsoft Exchange Console and disable the download of virus definitions