Some “light” or “compressed” versions are actually modified by pirates who bundle adware. You will finish installing Windows 10 only to find that your default browser is some unknown search engine, and pop-up ads appear on your desktop.
Even with the best compression tools (like 7-Zip on Ultra settings, LZMA2, or WinRAR), you cannot compress an already compressed file further without losing data. Trying to compress an .esd file (which is already at its theoretical minimum) will yield negligible results—maybe 1-2% smaller.
Conclusion from Tests: The absolute smallest functional Windows 10 installation that can still boot and run the setup process is roughly 1.5 GB to 2 GB if you strip out all drivers, languages, fonts, and non-essential components. Any claim of a 200 MB Windows 10 ISO is a mathematical impossibility unless the file is either: highly compressed windows 10 iso file download link
To understand whether a "highly compressed Windows 10 ISO" is plausible, we first need to understand how file compression works.
For advanced users, tools like NTLite (paid) or MSMG Toolkit (free) allow you to remove components from an official Windows 10 ISO after you download it. You can strip out: To understand whether a "highly compressed Windows 10
Resulting size: Can be as low as 1.8–2.2 GB for a functional, up-to-date Windows 10 Pro. Safety: As safe as your source ISO (always start from Microsoft).
To understand the risk, one must understand the technology. Resulting size: Can be as low as 1
Conclusion: If a file claims to be a full Windows 10 installer under 1GB, it is either a fake file, a destructive trojan, or a "lite" version stripped of so many features that it is unstable and unusable.