I downloaded the addon pack for NIS2009 it started to install then the instalation screen just vanishes. I clicked on the installer again and i get the message "Another installer in currently running, Please wait...try again" After a restart i checked to see if the addon pack was installed no luck. I tried clicking on the installer again same message as before. ok, downlaoded the addon pack again, same thisng as before, starts installing and then vanishes. Did norton hire Houdini to program for them. I can install any other software package. Why cant i get this done.