to build your rescue environment. This process downloads the necessary Windows PE components and creates a bootable drive with Macrium Reflect included.
you wish to back up.
However, "no official portable version" does not mean "cannot be used portably." High-quality portable functionality comes from a different angle: macrium reflect portable free high quality
Detailed steps for to the USB environment. A comparison of WinPE vs. WinRE performance benchmarks. to build your rescue environment