DO NOT run the setup program as administrator! It will elevate the tray app to admin and require UAC intervention upon startup. Since you cannot grant a tray app this premission during start up, it will be blocked by defender. Simply run the setup under YOUR login and make sure that the desktop shortcut AND the executable located in "C:\Program Files\SlySoft\AnyDVD\AnyDVD.exe" isn't starting as administrator. Right click the file and navigate to the compatibility tab and make sure the 'Run as administrator' checkbox is unmarked. If you were playing around with the last version and elevated the app to start as administrator, you'll need to back this out, even if you uninstalled. Somehow, Vista saves the "Run as administrator" option in the registry and will apply it future versions unless you manually backed out the changes. BTW, this ONLY applies if you're using UAC. If not, you'll probably not be having any issues but then again, you're box is open to a whole lotta other nasty stuff out there, beware!