Microsoft provides a tool that dynamically generates the correct ISO for your language and architecture.

Once you have your official bootable USB, here is how to install it:

The official ISO from Microsoft is approximately 5.2 GB to 5.8 GB . Anything significantly smaller (e.g., 1.5 GB) is a fake or stripped version missing critical components.

If you genuinely need a portable Windows environment for diagnostic or recovery work (like an IT technician), use or a reputable third-party tool:

The term "Portable" in this context usually manifests in one of two specific technical forms: