What Is a CAB File?

How to open, edit, and convert CAB files

What to Know

  • A CAB file is a Windows Cabinet file.
  • Windows opens them automatically, or you can use 7-Zip.
  • Convert to EXE with IExpress Wizard, a tool built-in to Windows.

This article describes what CAB files are, how to install or open one in Windows or another operating system, and how to convert one to EXE or another format.

What Is a CAB File?

A file with the .CAB file extension is a Windows Cabinet file (they used to be called Diamond files). They're compressed files that store data related to various Windows installations that might involve device drivers or system files.

The Microsoft Publisher program's Pack and Go feature can make CAB files that end with the PUZ file extension. Within it is everything included with the document, in the same archive format as CAB, so they can be treated just the same.

CAB files in Windows 10

The InstallShield installer program makes files with the CAB extension, too, but they're unrelated to the Windows Cabinet file format.

Some devices might use the CAB file extension to store firmware files.

How to Open CAB Files

Opening a Windows Cabinet file in Windows will automatically launch the file as an archive so you can see what's inside. Windows essentially treats it as a folder, and does so automatically; you don't need to download a CAB opener for Windows.

However, you can also open or extract CAB files with a file decompression tool. Going this route lets you open the file on other operating systems like macOS or Linux. A few free file extractors that work with CAB files include 7-Zip, PeaZip, IZArc, The Unarchiver, and cabextract.

If you have a PUZ file that came from Microsoft Publisher, you can open it with any of the file extractors just mentioned. If those programs aren't recognizing the PUZ file extension, either open the file unzip software first and then browse for the file or change the .PUZ file extension to .CAB and try again.

InstallShield CAB files aren't the same as Windows Cabinet files, but they can be extracted with unshield.

If you still can't open it, you might be confusing it with a similar file extension like CBA, CAA, or ABC.

Installing CAB Files in Windows

If you have an offline, downloaded Windows update file in the CAB format, another way you can install it is through an elevated Command Prompt. Type this command, replacing the path to the CAB file (within the quotes) with the path to the one you're using:

dism /online /add-package /packagepath:"C:\files\cabname.cab"

Don't press Enter until you've written the whole command. Regardless of any breaks in the command that you see above, only include spaces until you reach the very end.

You shouldn't use the DISM command to install language packs, but instead the lpksetup.exe tool, like this:

  1. Open the Run dialog box with the Win+R keyboard shortcut.

  2. Enter lpksetup (the first letter is a lowercase L).

    lpksetup Run command in Windows 10
  3. Select Install display languages.

  4. Choose Browse to locate and select the CAB file.

    Install or uninstall display languages window in Windows 10
  5. Select Next.

  6. Wait for the whole process to finish. It might take a while.

  7. You can close out of the Installing display languages screen when the Progress says "Completed."

To switch to the new language, go to Settings > Time & language, and then Language & region (W11) or Language (W10). In older versions of Windows, go to Control Panel > Clock, Language, and Region > Language.

How to Convert a CAB File

There aren't any file converter programs we're aware of that can do a clean CAB to MSI conversion. However, you might find help from other InstallShield users in the Flexera Community.

WSP files are SharePoint Solution Package files used by Microsoft SharePoint and compressed in the CAB format. You can rename the WSP file to CAB and open it like you would a Windows Cabinet file.

You can convert CAB to EXE with IExpress Wizard, a tool included in Windows. Open the Run dialog box with the Win+R keyboard shortcut and then type iexpress.

If you need to convert CAB to KDZ to get an Android firmware file in the right format, follow the instructions at BOYCRACKED.

More Information on the CAB Format

Windows might compress a CAB file with DEFLATE (like most ZIP files), Quantum, or LZX since the format supports all three compression algorithms.

Every CAB archive is compressed as a whole instead of each file individually. A CAB archive can hold up to 65,535 CAB folders, and those folders can contain an equal number of files.

When a CAB file is actually used by an installer, the files contained within it are extracted on an as-needed basis and in the order that they're stored within it.

A large file can be made into multiple CAB files so long as no more than 15 files span to the next CAB file. This means that you could have up to 15 files in one CAB file that span to the next CAB file in the series, and that one could even have up to 15.

CAB files are recognized by the first four bytes. If you open a CAB file as a text file with a text editor, you'll see "MSCF" as the very first four letters.

You can make a CAB file with makecab.exe, which is included in Windows. Running a command like this in Command Prompt would compress the file into a CAB archive:

makecab.exe C:\files\program.jpg C:\files\program.cab

You can read more on the Windows Cabinet file format from Microsoft's Windows Developer Center.

Can You Delete CAB Files?

It might be tempting to delete CAB files from your computer when you see dozens or even hundreds of them in one folder. What's extremely important before deciding this is to understand where the CAB files are and whether or not they're important.

For example, CAB files in the system32 folder should be kept no matter what. Trying to decipher what's important in here can be really confusing, and making a wrong decision could cause problems later on since Windows might need the CAB file you deleted to fix a corrupt file.

However, CAB files that are related to iTunes, DirectX, or some other third-party program can probably be safely deleted without causing system damage, but they might make the program stop working or prevent certain tasks from running. If the program stops working after deleting the CAB files, just repair it or reinstall it, but chances are that these kinds of files are only temporary.

Due to the nature of what CAB files are, it's common to see them within the setup files of a program. For example, the Microsoft Office installer includes several CAB files, some of them pretty large. If these are removed, it would corrupt the installer and you wouldn't be able to use those setup files to install MS Office.

Some software will dump cab_xxxx files into the C:\Windows\Temp\ folder while installing updates or doing some other system related task. It's completely safe to remove CAB files in this location unless your computer is actively updating or installing software (since they might be being used at that time).

If you can't delete them because they keeping regenerating (e.g., the C:\Windows\Logs\CBS\ folder keeps making LOG and CAB files), try deleting the oldest LOG file there (or all of them) and then remove every CAB file from C:\Windows\Temp\.

  • Can CAB files be dangerous?

    Sometimes. Like most file types, CAB files can contain viruses, so scan the files you download online with antivirus software before running or opening the files.

  • How do I fix a CAB file that's corrupted?

    First, run your antivirus software to get rid of any malware. If that doesn't fix the problem, use a tool like Advanced CAB Repair.

  • What is the command to uncompress a Windows CAB file?

    dism /online /add-package /packagepath:"C:\files\cabname.cab"

    Replace C:\files\cabname.cab with the correct file path. You must be logged in as an administrator for the command to work.

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