Delete all the contents inside downloads folder then try this
To overcome this issue, change the timeout setting for LiveUpdate to extend the session period.
1. As per OS, browse to
Windows 2003: Default location is C:\Documents and Settings\All Users\Application Data\Symantec\Liveupdate
Windows 2008: Default location is C:\Programdata\Symantec\Liveupdate.
2. Open Settings.Liveupdate, find
PREFERENCES\INTERNET_CONNECT_TIMEOUT=45
PREFERENCES\INTERNET_READ_DATA_TIMEOUT=45
Change the default setting of 45 to a larger number, for example 300.
3. Save Settings.Liveupdate.
4. Run LiveUpdate to verify success.