If you only have access to the (.exe) on a machine that does have internet, you can sometimes "trick" it: Run the online installer.

To get your setup running without an active internet connection, you generally need the standalone (offline) installer . Most users mistakenly download the "Online Installer" (a tiny 3MB file), which fails if the target machine is offline. Why Use the FortiClient 6.4 Offline Installer?

: If the VPN won't connect after an offline install, check the Device Manager . Look for the "Fortinet Virtual Adapter." If it has a yellow exclamation mark, you may need to disable Secure Boot in your BIOS or update your Windows root certificates.