DIAG file format description

Many people share .diag files without attaching instructions on how to use it. Yet it isn’t evident for everyone which program a .diag file can be edited, converted or printed with. On this page, we try to provide assistance for handling .diag files.

1 filename extension(s) found in our database.

.diag - Microsoft Windows Troubleshooting Pack Designer Data

The DIAG data files are related to Microsoft Windows SDK. The DIAG file is a Microsoft Windows Troubleshooting Pack Designer Data. The Windows Troubleshooting Pack Designer is provided as part of the Windows software development kit (SDK).

Microsoft Windows SDK
Data files
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Microsoft Windows Troubleshooting Pack Designer Data related extensions:
Microsoft SQL Server Integration Services Package
Microsoft Channel Definition Format Data
Microsoft Access Database Lock
Microsoft Frontpage Linkbar Data
Microsoft Frontpage Theme Package
Microsoft Surface Calibration Hash

Naturally, other applications may also use the .diag file extension. Even harmful programs can create .diag files. Be especially cautious with .diag files coming from an unknown source!

Can't open a .diag file?

When you double-click a file to open it, Windows examines the filename extension. If Windows recognizes the filename extension, it opens the file in the program that is associated with that filename extension. When Windows does not recognize a filename extension, you receive the following message:

Windows can't open this file:


To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select one from a list of programs that are installed on your computer.

To avoid this error, you need to set the file association correctly.

The .diag file extension is often given incorrectly!

According to the searches on our site, these misspellings were the most common in the past year:

dag, dia, dig, siag

Is it possible that the filename extension is misspelled?

Similar file extensions in our database:

Psion Organiser Diary Document
Digilink Format Audio Data
World Championship Poker 2 Game Data
Siag Spreadsheet Document
Dagra Document
Sound Designer Audio

Operating systems

DataTypes.net currently supports the following operating systems:

Windows XP/Vista, Windows 7/8/10, Windows 11, CentOS, Debian GNU/Linux, Ubuntu Linux, FreeBSD, macOS, Mac OS X, iOS, Android

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If you have useful information about the .diag file format, then write to us!

DataTypes.net >> DIAG file