Factory resetting your firewall is a drastic step that should only be taken when necessary and with careful consideration. It's important to note that a factory reset should not be taken lightly, as it will erase all configurations and data on the firewall. If you decide factory resetting is the route you need to take, make sure to back up your existing configuration and keep a tech support file on hand for that device.
Steps to Factory Reset Your VM-Series Firewall
1. Login to the CLI and enter the following command:
debug system maintenance-mode
Once entered, your VM-Series will reboot.
2. Continue maintenance mode and select "Factory Reset"
3. Select and enter while on "Factory Reset". Your firewall will then go through the reset process.
4. Once complete, select and enter on "Reboot".
Your VM-Series Firewall will then reboot normally and you will have a fresh image of PAN-OS. Please wait for the "PA-VM:" login prompt to enter the default credentials.