I don't have access to the OS. The guys that used to work here, that no longer work here, installed the device and I have no idea where they put the OS stuff. All that I have is the Quick Start Guide with a CD that states GuardianOS 5.2 User CD. As I understand it, the file needed to reference for the OS install is a .gsu file; I could not find that file on the CD. I believe in order for me to get the necessary OS files from Support I have to renew the maintenance/warranty. It's not worth the money to do that.