You cannot upgrade to 3.66 from an earlier version..you need to do a clean install..You may be able to email support to get the update file...3.66 upgrade fails or just poor documentation.
I've applied the 3.66 upgrade manually but when I run the application the version number displayed is 3.09.03. Another 'feature' that backs up the 'not upgraded' product is there are a lot less model numbers of the cameras we are using and none of the cameras (12) that worked before I had to rebuild the boot disk can connect (because the model number is not valid?)
try the update file..if that fails reboot the system and try the uninstall again.Just went to W7 control panel, Uninstall... funny the program listing shows version 3.66 as the 'installed' version. Then the uninstall fails..