The msmpeng.exe file is a key process within Windows Defender. Windows Defender is a built-in program on Microsoft Windows and provides basic spyware, malware, and virus protection on a variety of operating systems. The process was first released with Windows Vista. Upon the release, previous versions of Windows operating systems were able to download a free update to receive this program if desired. Other file names associated with this process are mpeng.exe.

File name: Msmpeng.exe
Application: Windows Defender
Publisher: Microsoft
Rating: 3 stars based on 472 votes
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Possible causes of Msmpeng.exe errors

These errors are frequently caused by conflicts with the file or installation profile, misuse of the file or respective directories, or a malicious attack on the system.

  • When conflicts arise on the profile or with the file, the application may be unable to transmit data between the necessary files.
  • When a file or directory is misused or damaged, the application as a whole may be unable to load.
  • Malicious attacks or infections on the system may render the entire system frozen or unable to perform any necessary computing functions.
Regardless of the cause, determining the best solution should be the first action step when noticing any system-related computer errors.

Is Msmpeng.exe a dangerous file (virus, malware, spyware)?

In most cases, the file is considered to be safe. However, files do become corrupt at times and some malicious files are disguised to represent known, secure system files. When that happens, they can be very difficult to detect and remove, but using a comprehensive system scan usually detects them and allows you to safely remove them.

Known Msmpeng.exe error messages

Msmpeng.exe error

Common error messages users may see include:

  • File not found: Msmpeng.exe
  • Cannot find file: Msmpeng.exe
  • Device not recognized missing Msmpeng.exe file
As the file is associated with USB connections to the computer, a keyboard, mouse, or other piece of hardware connected to the machine through a USB cable may be causing the error or may be unable to function properly due to the error.

Should I stop the Msmpeng.exe task or process within the Task Manager?

Unless you have experience managing the processes and tasks on your machine, it is best to allow a system scanner or registry scanner to handle those tasks. Many of the tasks are required for performing specific operations on your machine and removing them may cause your program or entire computer to malfunction or reboot.

Should I download a new copy of the Msmpeng.exe file?

The only time you should ever download a new version of a system file is when it comes through an application update or from the publisher directly. Be very cautious when downloading system files from third-party websites as they may contain additional software that you would install without knowing. This could cause an even larger issue than the error you are getting from this file!
WARNING: If you already downloaded a new file from an external site,
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Best way to fix Msmpeng.exe errors

When these errors occur, verify if any new hardware or software has been added. If so, simply removing the new hardware or software may resolve the issue. If not, follow the steps below.

  1. Scan for any driver updates for new equipment. If new equipment or programs have been loaded, they may require updated drivers. Download new, secure drivers and perform a clean system restart.
  2. Download and install updates for the operating system. Regardless of the operating system version you are using, it is always considered good practice to install the latest security updates.
  3. Use anti-virus and anti-malware applications. Most virus scanners will protect your machine from basic threats. To increase your protection, use a malware scanner as well.
If the above steps fail to resolve the issue, it may be due to outdated hardware or software.

More information about Msmpeng.exe

Most errors with this file are from users experiencing slowness or the inability to perform certain tasks. Additionally, some applications fail to load properly for users when Windows Defender is installed. When this happens, it may be a version issue. If the version is properly updated and installed with the operating system you are currently using, an infection or malicious attack may be present on your system.

Another explanation for anyone who is experiencing issues with this data file is to be careful of infecting other files. One of many data files that may be influenced by a new trojan or spyware invasion is ntoskrnl.exe. When you notice errors or viruses with a single file, chances are good that it will spread to the rest of the system.


Lead Editor (Bio)

Allen Quinn, Editor
Hey everyone, Allen here. I've been involved in tech support roles for more than 15 years and understand the pains and frustrations associated with broken computers. It's my goal to provide you with the help and knowledge you need to get and keep your computer in working order.


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