This does compress the ISO but compresses the installed Windows files on disk using algorithms like XPRESS or LZX .
You can manually create a smaller ISO using DISM :
| Format | Typical Compression Ratio | Decompression Speed | Use Case | |--------|--------------------------|---------------------|-----------| | ZIP | ~10–20% smaller than original | Fast | Archival, sharing | | RAR | ~15–25% smaller | Medium | Archival | | 7z (LZMA2) | | Slow | Long-term storage | windows 10 iso compressed
Do you have any questions about compressing Windows 10 ISO files? Share your experiences or ask for help in the comments!
| Method | Final Size | Bootable? | Install Speed | Easy to Do? | |--------|------------|-----------|---------------|--------------| | Original ISO | 5.5 GB | ✅ Yes | Normal | N/A | | 7z archive | 3.8 GB | ❌ No (needs extract) | N/A | ✅ Very easy | | ESD-based ISO | 3.2 GB | ✅ Yes | Slow (2–3x longer) | ⚠️ Moderate | | ZIP archive | 4.8 GB | ❌ No | N/A | ✅ Very easy | | Compact OS (post-install) | N/A | N/A | N/A | ✅ Easy | This does compress the ISO but compresses the
Microsoft uses internally. An ESD file is a highly compressed Windows image.
⚠️ Risks:
dism /Export-Image /SourceImageFile:install.wim /SourceIndex:1 /DestinationImageFile:install.esd /Compress:recovery
An official Windows 10 ISO from Microsoft is already moderately compressed (using standard ISO 9660 + UDF ). However, "compressed" usually refers to: | Method | Final Size | Bootable