We are running a SBS2011 server and it has been running great for a month. Recently we installed an AV on the SBS but it is being managed by another server on the network. Shortly (about 3 days to a Week) after the install the users were complaining about slow network drive connection on the SBS server. Then the complaints escalated and user loose connection to their remote drive located on the SBS server. You are then unable to log into the server and when we logged on locally we saw and error for the Remote Procedure Call services stopping inappropriately. The services would not start back so the server was then rebooted and this resolved the user outage. This has happened 3 times since the Anti Virus was installed. I specifically didn't put the AV Brand in this request to see if anyone has had the same or similar issue with Any AV if you need specifics on the Brand please ask and I will provide.