What is expand.exe file and Command-Line Info

Expand.exe is a genuine Windows file that is a command-line utility that allows to expand or compress files.   This command also allows users to collect compressed files from distribution disks and it can operate directly from the Windows Recovery Console, but with a separate set of parameters.

File Size and Location

Expand.exe can be located in the C:\Windows\System32\ folder, in Windows 10 or older versions and it can be identified as Win32 file type. The Expand.exe file usually takes up around 65 KB of space.

Quick Overview

File Name: Expand.exe
File Description: LZ Expansion Utility
Type: Executable Application
File Size: 52 KB
File Version: 5.00 (WinBuild.160101.0800)
Product Name: Microsoft® Windows® Operating System
Copyright: Microsoft Corporation
Language: English

This is what an authentic expand.exe file looks like:

Is expand.exe Malware?

There is very little chance that expand.exe could be malware or virus.  There are few easy steps that can be used to find out whether expand.exe is malware or a genuine file:

1) Check the file location: An original expand.exe will be always located under the C:\Windows\System32\ folder. If the file is located outside the Windows folder then it may be a suspicious file.

2) Check the file size: As mentioned above, the average file size of expand.exe is about 65 KB. A malware or virus may pretend to be a genuine file but do check its file size. If it is in MB then it must be malware or a virus.

Run command to reboot Windows.

Expand.exe Parameters

The expand.exe executable is responsible for the expansion of compressed files and it is actually an LZ Expansion Utility. Here are few sample command lines that can be used with Expand.exe:

expand [Parameters] <source> [<destination>]
expand <source>.cab /f:<files> [<destination>]

1. /r:  This command line is used to Rename the decompressed file.
2. source: This parameter can comprise a drive letter and a colon, the directory name, the file name, or all of them together. This command identifies the file to be expanded and wildcard characters can be used.
3. destination: This parameter identifies where the files are to be decompressed.
4. /f: <files>: Identifies the files to be expanded in a cabinet (.cab) file. The user can also use wildcards.

Recovery Console Expand.exe Syntax

The Windows Recovery Environment was created on the functionality of the Windows Preinstallation Environment and it is an environment meant for repairing common causes of unbootable operating systems.

1. source: This command is used to expand a particular file but makes sure to not to include any wildcard characters.
2. destination: This parameter identifies where the files are to be decompressed and the default destination is the present directory.
3. /y: This will directly overwrite any existing file without showing any warning message.
4. /d: Allows the user to view the list of the files in the source location, with no extraction or expansion of said files.
5. /f: <files>: Identifies the files to be expanded in a cabinet (.cab) file. If there are multiple files in the source, then the exact files to be expanded must be identified.

Other similar files:

Findstr.exe, Wusa.exe, Wevtutil.exe, esentutl.exe