1. Stop the SEPM server service.
2. Go to "…\Inetpub\content\{C60DC234-65F9-4674-94AE-62158EFCA433}" folder and deleted all the sub folders
3) Go to C:\Program Files\Common Files\Symantec Shared\SymcData\ and delete the following folders:
sesmipsdef32
sesmipsdef64
sesmvirdef32
sesmvirdef64
4)In the registry, navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\InstalledApps.
Delete these keys
SymcData-sesmipsdef32
SymcData-sesmipsdef64
SymcData-sesmvirdef32
SymcData-sesmvirdef64
5). In the registry, navigate to and delete the following keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\SharedDefs\SymcData-sesmipsdef32
HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\SharedDefs\SymcData-sesmipsdef64
HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\SharedDefs\SymcData-sesmvirdef32
HKEY_LOCAL_MACHINE\SOFTWARE\Symantec\SharedDefs\SymcData-sesmvirdef64
6). Start the SEPM service back up.
7). Run Live update from within the Symantec Endpoint Protection Management console.
Symantec Endpoint Protection Manager 11.x is not updating 32 or 64 bit virus definitions.http://service1.symantec.com/support/ent-security.nsf/docid/2008041516215948