Go to Microsoft’s official download page (search "Download Windows 10 Disc Image" or use the Media Creation Tool). Avoid any third-party mirror.
After downloading the legitimate ISO:
Result: ~4.5 GB ISO → ~3.2–3.8 GB 7z file. (Not “highly compressed” to <1GB — that’s impossible without deleting critical files.)
For splitting into smaller parts (e.g., for upload):
To reduce ISO size before compression (advanced, risky): download windows 10 iso highly compressed
If you genuinely need a smaller download:
Option 1 – Use the Media Creation Tool
Option 2 – Download the Official ISO from Microsoft
Option 3 – Use Windows 10 Compact OS (after install) Go to Microsoft’s official download page (search "Download
Option 4 – Download Windows 10 Enterprise LTSC (if eligible)
You don’t need to download a risky pre-compressed ISO. You can build your own lightweight Windows 10 source using Microsoft’s own tools. Here is the 100% legal and safe method.
A: Yes. If you compress the already installed Windows folder (Compact OS or NTFS compression), read speeds may drop 5-10%. But a pre-compressed ISO does not affect runtime speed—only the download and extraction time.
dism /Export-Image /SourceImageFile:C:\mount\install.wim /SourceIndex:1 /DestinationImageFile:C:\compressed\install.esd /Compress:recovery Result: ~4
Final size after ESD conversion: ~2.1 GB. This is the smallest official-style image you can achieve without breaking Windows Update.
A: .esd (Electronic Software Download) is Microsoft’s own highly compressed format—up to 30% smaller than .wim. Legitimate Windows update files use .esd. Some repackers distribute .esd directly.
After download, right-click → Properties → Digital Signatures. If none exist, that’s a red flag.
For open-source lite versions, compute SHA-256:
certutil -hashfile tiny10.iso SHA256
Compare with the value posted by the developer on Twitter/GitHub.