From time to time, our AutoDesk users experience almost a couple minute halt/hang when working in Land Desktop 2008 and Civil 3d 2008. After this time, everything is back to normal. There is thought that sometimes a large amount of data is moved causing slow downs. However, looking at the file audit trail around the time it occurs, there are no major moves/deletes. I have seen posts regarding antivirus and performance issues, so I would like to tweak my AV and rule out any issues with this. Are there any safe extensions that can be excluded to prevent performance issues. We are running Symantec Endpoint Protection 11 on all XP clients and the Windows Server 2003 SP2 file server.