Opening DIAGCAB files
Did your computer fail to open a DIAGCAB file? We explain what DIAGCAB files are and recommend software that we know can open or convert your DIAGCAB files.
What is a DIAGCAB file?
The DIAGCAB file format was developed by Microsoft as a data and archive file format for Windows Vista, 7, 8 and 10. These .diagcab files are generated by the makecab tool, which is a Windows application that's built into these Windows OS versions. The data stored in a DIAGCAB file can be viewed by using the Microsoft Support Diagnostic Tool, which is another application that's also available in these Windows OS versions.
The Windows Troubleshooting service uses these .diagcab files, which was introduced in Windows Vista. This application assists users in detecting problems and repairing system issues. This can also be used to send error logs and reports to Microsoft servers for analysis.
Similar to a CAB file, a .diagcab file may contain multiple resources and multimedia content items. It's best to leave these DIAGCAB files alone, in order to ensure that the Windows Troubleshooting service and the Microsoft Support Diagnostic Tool can properly access the resources and data stored in these .diagcab files when needed.
Software that will open, convert or fix DIAGCAB files
Try a universal file viewer
In addition to the products listed above, I would suggest that you try a universal file viewer like Free File Viewer. It can open over 200 different types of files - and very likely yours too! Download Free File Viewer.