Microsoft officeMicrosoft Excel 2010 slow to open files on network KB2523021 Posted on 28/07/2011 by Computer If you are having problems when Microsoft Excel is taking excessively long when attempting to open a file on a network folder, try removing the security update KB 2523021 Stop teamviewer port 80 443 conflict Sophos NAC only installs on Windows 2003 or 2008 standalone server not SBS