We have installed Symantec Endpoint Protection (12.1.4013.4013) last July and we noticed that, since then, many computers we manage went slow. After investigation, we found that this is due to the disk usage which becomes frequently at 100%. The machines are then hanging and this might be for few seconds or few minutes. The AV was installed by an external company and they have applied the default "Balanced" template.
We have disabled the Outlook Add-In which made Outlook usable as users were getting stuck whenever they use it since Symantec Endpoint Protection installation. That helped for Outlook but the overhaul performance is not good at all. When I remove Symantec Endpoint Protection and install Microsoft Security Essentials then everything works Perfectly. It is just that when I install Symantec Endpoint Protection then everything goes wrong.
We use Microsoft Forefront Protection as the AV of the servers and it performs well without causing performance issues. We have decided to not use that on the Desktops so that we can have additional layer of protection by not using the same AV technology everywhere and that is why we went with Symantec.
I believe that the Symantec AV can be performing much better by tweaking it. So, Are there any recommendations you can give to help us having the Symantec AV installed but with high performance PCs?