We had a major issue where Symantec Anti-Virus would not update some (but not all) 64 bit clients. To make a long story short, it ended up being corrupt files that had previously been downloaded by Live Update, and lived in the LiveUpdate directory on the server. To clear up the problem we had to…
In LiveUpdate Administration Utility ( v126.96.36.199 )
Tools – select “Clean Up Download Directory.”
Options – select “Retrieve new and previously downloaded updates.”
Go into your LiveUpdate folder and make sure all the files are gone (delete any that are still there.)
Back in the LiveUpdate Administration Utility click “Retrieve” on the top right corner.