Seems like the defs are corrupted and its not updatting

run the rapid release and this should fix the issue.

http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2005041813344248?Open&docid=2003100110562848&nsf=ent-security.nsf&view=docid

Hi Panos83,

Are there any messages appearing in the Windows Application Event logs which state why the update failed?  That would be the first place I would look.  The error code there should correspond to a number of public articles for known issues.  SAV 10.1 MR4 is relatively old technology at this point and the common points of failure and the ways to fix them are pretty well known.   

In case the Rapid Release solution proposed above does not work, Symantec Technical Support have access to tools which can determine if AV definitions have become corrupt, and another tool called Rx4Defs which can solve the problem.

Finally: I really do recommend that you move away from SAV 10.1 MR4 and upgrade to the latest release, 10.1 MR9.  This contains several hundred enhancements and improvements over your existing version.  See the following release note for details:

Release notes for Symantec Client Security 3.1.x and Symantec AntiVirus 10.1.x

Plus, MR4 has known vulnerabilities that can be exploited by threats circulating in the wild.  See the information on Symantec AntiVirus Malformed RAR and CAB Compression Type Bypass and Symantec AntiVirus Corporate Edition Local Elevation of Privilege. Keep your defences up to date!

Thanks and best regards,

Mick