Here is an "explanation" I got back from Curious Labs: I can't tell you which is the culpret Norton or Poser let me forward this to QA. I have Norton 2000 on a windows machine running 95-98 this doesn't occur with me and may be a false message from Norton. If you installed with Norton running you'll have errors, virus utilitys and disk utilitys cause coruption with installs. WIN:Use control/alt/delete and the task manager that appears to close (end task) some of these tasks, leave if possible only the explorer and the systray running, reinstall. This assures that your install is clean, if your are installing Poser to a different directory then you must assign it a folder example d:/Poser 4, the installer will ask "this folder does not exist, shall I create it?" This assures you that it is a correct install. MAC:In extension manager make an extension set copy of OS base, rename to Installer. Turn off all of the extensions but Apple CD-ROM and QuickTime and QuickTime power plug, reinstall. Something in you system has conflicted with the proper install of the program. This set can also be used to check on further conflicts. Tech