I have an 8GB USB drive and want to use Ventoy to keep both a Windows 11 installer and a Linux distribution on it. The Windows 11 ISO nearly fills the drive by itself, so there is not enough room for both. What are the practical ways to reduce the ISO as much as possible? I have heard about converting install.wim to install.esd using DISM or wimlib, and I would like to know which provides better compression, along with any other useful methods.
2 Answers
You can use a tool such as NTLite to remove Windows editions you do not need from the ISO. For example, you could keep only Pro and remove Home, Education, Single Language, and Workstations editions. This can make a noticeable difference; one reported example reduced a Windows 11 IoT LTSC ISO from about 6.38GB to 4.35GB.
In practice, buying a 16GB or 32GB USB drive is usually easier and safer than heavily modifying the Windows installer. They are inexpensive, and keeping the original ISO avoids compatibility problems caused by removing files or editions.
There is also a use case for shrinking the image when the installer must remain on a FAT32 boot device, since the standard install.wim can exceed FAT32's 4GB file limit. However, reducing it enough may require removing a lot of content, so it may not be worth the effort compared with using a larger drive or a compatible split-image method.
Removing unused editions is one option, but I was also wondering whether there are additional ways to reduce it further, such as using ESD compression or removing other installer components.