Hi,
Remove liveupdate from add/remove programs
Delete the following Liveupdate folders if present else ignore
c:\Program Files\Symantec\LiveUpdate
c:\Documents and Settings\All Users\Application Data\Symantec\LiveUpdateInstall liveupdate
Do a repair of SEP from add/remove programs
Reboot
Start-run
Type luall.exe
If didn't work go through thread for possible solution.
https://www-secure.symantec.com/connect/forums/common-liveupdate-errors-client-side