Symantec AntiVirus scans take too long (hours) to complete. When you try to view them at the History screen, you are unable to do so.
Solution:
A solution that works in these cases is to delete the log files in the Logs folder. This folder's location will depend upon the Operating System in use. When you delete the log files, you will also "lose" any Event log, Virus History, and Virus Sweep History as well. This will have no effect on the operations of Symantec AntiVirus.
For Windows 2000/XP users to see the Application Data folder, you will need to turn on the Show Hidden files and folder option.
Before you install Symantec AntiVirus, uninstall any existing anti-virus software on your Windows computer, including previous versions of Symantec AntiVirus and LiveUpdate.
Open the following folders to access the Logs folders.
Windows 2000/XP:
C:\
Documents and Settings
All Users
Application Data
Symantec
Norton AntiVirus Corporate Edition
7.5
Logs
Windows 9x:
C:\
Program Files
Norton AntiVirus
Logs