Incorrect permissions cause this problem. To fix the problem, follow the directions in the document :
http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2002103013521548
If the problem persists, manually uninstall the previously installed version of the program, and then reinstall Symantec AntiVirus server.
For manual uninstallation :-
http://service1.symantec.com/SUPPORT/ent-security.nsf/docid/2002031914291648