To create the bootable media, you first need the main application. Note that Macrium Reflect Free v8.0 has reached its end of life and no longer receives feature updates .
The ISO you create is — it’s a bootable recovery environment tied to your Reflect version, but it can be used on any PC to restore images.
If you have a specific legitimate use case — like recovering a PC without installing Reflect first — I’m happy to write a detailed, safe, step-by-step guide using officially available tools. Just let me know.
If you buy a new PC with modern hardware (like NVMe Gen 5 drives), recreate your Rescue Media to ensure it has the latest drivers.