I'm trying to update the clients but I cannot do it, can you guys help me with this? Here part of the log:

Wed Oct 29 09:55:17 2014 : AUTH DLL LOCATION: IU will read the DLL location from registry - SSEIUAuth
Wed Oct 29 09:55:17 2014 : REG FAILURE: Failed while opening the key  from registry. Return code: 2
Wed Oct 29 09:55:17 2014 : DEPLOY DLL LOCATION: IU will read the DLL location from registry - SSEIUDeploy
Wed Oct 29 09:55:17 2014 : REG FAILURE: Failed while opening the key  from registry. Return code: 2
Wed Oct 29 09:55:17 2014 : IGNORE ENTRY: Ignoring entry for VIRSCAN.zip because of registry read failure. Error occurred while reading the path for the Authorization DLL from the registry.
Wed Oct 29 09:55:17 2014 : The product corresponding to this entry in iuconfig.xml is not installed on the system.

thanks!

What Exact SEP version are you using ?

Intelligent Updater fails to update SEP MR4 or older client definitions when using the Version 5 updater.

Which SEP version?

12.1.5

Have you try to reinstall sep client ?

Download the Symantec Help (SymHelp) diagnostic tool to detect Symantec product issues

Do you have tamper protection enabled? can you try disabling it and then running the upgrade?