File extensions exe : The EXE executable (program) file

An executable file is a program that can be executed on the various Microsoft operating systems (Dos,windows 98/xp/vista).

What is Msiexec.exe?

Msiexec.exe is part of the Windows Installer. This is used by many pieces of software for the installation routine.


It is common for virus and spyware to disguise themself as the genuine one.
The following malware is known to disguise itself as the genuine msiexec.exe:

Troj/Oscabot-A (%SystemRoot%)
Troj/Imoni-B (%SystemRoot%)
W32/Rado-A (%SystemRoot%)
VBS/Yosenio-A (%SystemRoot%)
Win32/Oscarbot.B (%SystemRoot%)

Common Errors:
The MSIEXEC.EXE file is linked to a missing export MSI.DLL:222.
Cannot launch C:\Windows\System\MSIEXEC.EXE, a device attached to the system is not functioning.

Product name:  Windows Installer - Unicode

Description: Windows® installer

Manufacturer:  Microsoft Corporation

File extensions exe : The EXE executable (program) file

An executable file is a program that can be executed on the various Microsoft operating systems (Dos,windows 98/xp/vista).

What is MsMpEng.exe?

MsMpEng.exe is part of the Windows Defender anti-spyware software. It is performing spyware scans and protecting your system from spyware in the background. It is also installed as part of Windows Live OneCare.

Common Errors:

High cpu usage
If the process with high cpu usage , it is recommended that you uninstall or turn off Windows Defender.


Product name:  Microsoft Malware Protection

Description: Service Executable

Manufacturer: Microsoft Corporation

File extensions exe : The EXE executable (program) file

An executable file is a program that can be executed on the various Microsoft operating systems (Dos,windows 98/xp/vista).

What is msnmsgr.exe?

MSN Messenger/Windows Live Messenger software.

It is common for virus and spyware to disguise themself as the genuine one.
The following malware is known to disguise itself as msnmsgr.exe:

W32/Rbot-AVP (%SystemRoot%)
W32/Mytob-A (%SystemRoot%System32)
W32/Annew-A (%SystemRoot%System32)

Common Errors:
msnmsgr.exe - Entry Point Not Found. The procedure entry point IsThreadDesktopComposited could not be located in the dynamic link library USER32.dll.
High cpu usage.

Runtime Error!
Program: C:/Program Files/Windows Live/Messenger/msnmsgr.exe
This application has requested the Runtime to terminate it in an
unusual way.
Please contact the application's support team for more information.

Product name: Messenger

Description:Windows Live Messenger

Manufacturer:Microsoft Corporation

File extensions exe : The EXE executable (program) file
An executable file is a program that can be executed on the various Microsoft operating systems (Dos,windows 98/xp/vista).

What is MSASCui.exe?

MSASCui.exe is part of the Windows Defender anti-spyware software. It provide virus/spyware scan.

Common Errors:
MSASCui.exe - Unable to locate component (Vista)
MSASCui.exe - Bad Image
The application or DLL C:\Windows\system32\Winhttp.dll is not a valid windows image. Please check this against your installation diskette.

Product name: Microsoft Forefront Client Security

Description:Microsoft Forefront Client Security User Interface

Manufacturer: Microsoft Corporation

File extensions exe : The EXE executable (program) file

An executable file is a program that can be executed on the various Microsoft operating systems (Dos,windows 98/xp/vista).

What is mdm.exe?
Mdm.exe is the Windows Machine Debug Manager. Mainly for debugging scripts in Internet Explorer.

How to Turn Off the Machine Debug Manager:
1 Open Internet Explorer.
2 On the Tools menu, click Internet Options.
3 Click the Advanced tab.
4 Click to select the Disable script debugging check box, and then click OK.


It is common for virus and spyware to disguise themself as the genuine one.
The following malware is known to disguise itself as mdm.exe:
W32.Sdbot.APE (%SystemRoot%)
W32.Unubot.B (%SystemRoot%)
W32.Bckdr-QJR (%SystemRoot%)
W32.Agobot.AQ (%SystemRoot%System32mdm32.exe)
W32.Rbot.AIJ (%SystemRoot%System32mdm32.exe)

Common Errors:
MDM.exe hogging memory
MDM.EXE stops web forms

Product name: Microsoft® Visual Studio .NET

Description:Machine Debug Manager

Manufacturer: Microsoft Corporation