This page was for the previous PowerScripts Updater, which installed PowerScripts 3.7 and older. It isn't needed any more.
PowerScripts now installs with one small file you drop onto Illustrator, with no installer app and no administrator rights. It also moves you from 3.7 to the newest version, keeping your licence and settings:
IT administrators who need a signed ZXP file for their own deployment tools can email support@o2creative.co.nz.