DDI is DiskDupe disk image. This file format is deprecated. It contains disk image created in DiskDupe. .DDI file type is not actively used now. It is obsolete. DDI file extension is associated with 3 file types. A DDI file extension is related to 3 formats. Understanding these formats is key to handle files with a DDI extension. DDI files were developed by Unknown Developer. They are popular in China. Most DDI users run Windows 10. Many use Google Chrome browser.
When you double-click a DDI file, Windows checks the extension. If Windows recognizes the extension, it opens the file. If not, you must select a program to open it. We try to assist with handling DDI files. Many share these files without instructions. This makes it hard to edit, convert or print them. Our goal is to offer guidance on using .ddi files.
The user could copy this file to disks. They selected it as the data source when duplicating. Different DiskDupe versions saved DDI files differently. Version 5 used a 1280 byte header. Version 7 used a 9216 byte header. You can open a DDI file with DiskDupe. But it does not run on modern Windows.
DiskDoubler