Razer does not officially provide a standalone offline installer for Razer Cortex . The standard Razer Central
When you run the online installer, it immediately begins downloading a much larger .exe or .msi package to your %temp% folder (usually C:\Users\[YourName]\AppData\Local\Temp ). Before the installation completes, copy that large file (which is the offline installer) to a safe folder like D:\Installers\ .