Compact.exe /CompactOS:always This reduces the footprint by 1.5GB–2GB, but not to 100MB. Size: ~780 MB compressed (ZIP) → ~2.2 GB installed. What's removed: Windows Defender, Recovery image, Speech, Fax, most languages, Internet Explorer, Windows Mail. What works: Networking, basic drivers, Registry, Control Panel.
| OS Name | Size | Description | |---------|------|-------------| | | 16 MB | Graphical desktop, boots to RAM, runs on a 486 processor. | | SliTaz | 50 MB | Full GUI with Firefox-like browser, media player, and text editor. | | Puppy Linux (BionicPup) | 300 MB | Slightly larger but self-contains drivers and can run from a 256MB USB. | | KolibriOS | 1.4 MB | Written entirely in assembly. Boots in 2 seconds. No Windows compatibility. | windows 8 highly compressed 100mb updated
This is the smallest functional version of Windows 8.1 you can find. Search for "TeamOS Tiny8" (a respected modding forum). It is not 100MB, but it will install on a 4GB USB drive. While not Windows 8, LTSC is lighter than normal Windows 10/11. It has no bloatware (no Candy Crush, no Cortana). Install size is ~8GB, but after removing hibernation and pagefile, you can get down to 5GB. Still far from 100MB. Part 4: Real 100MB Operating Systems (Not Windows) If your actual goal is an OS that fits on a floppy disk or an old router (100MB limit), use Linux, not Windows. Compact
Compact.exe /CompactOS:always This reduces the footprint by 1.5GB–2GB, but not to 100MB. Size: ~780 MB compressed (ZIP) → ~2.2 GB installed. What's removed: Windows Defender, Recovery image, Speech, Fax, most languages, Internet Explorer, Windows Mail. What works: Networking, basic drivers, Registry, Control Panel.
| OS Name | Size | Description | |---------|------|-------------| | | 16 MB | Graphical desktop, boots to RAM, runs on a 486 processor. | | SliTaz | 50 MB | Full GUI with Firefox-like browser, media player, and text editor. | | Puppy Linux (BionicPup) | 300 MB | Slightly larger but self-contains drivers and can run from a 256MB USB. | | KolibriOS | 1.4 MB | Written entirely in assembly. Boots in 2 seconds. No Windows compatibility. |
This is the smallest functional version of Windows 8.1 you can find. Search for "TeamOS Tiny8" (a respected modding forum). It is not 100MB, but it will install on a 4GB USB drive. While not Windows 8, LTSC is lighter than normal Windows 10/11. It has no bloatware (no Candy Crush, no Cortana). Install size is ~8GB, but after removing hibernation and pagefile, you can get down to 5GB. Still far from 100MB. Part 4: Real 100MB Operating Systems (Not Windows) If your actual goal is an OS that fits on a floppy disk or an old router (100MB limit), use Linux, not Windows.