What is dllhost.exe

dllhost.exe is a system process in Windows that is responsible for launching and managing COM (Component Object Model) objects. It is used to host dynamic libraries (DLLs). You can learn more about how it works from our material.

Main functions of dllhost.exe

  • Launching and managing COM objects;
  • Working with DCOM (Distributed COM) – a technology that allows applications to work over a network;
  • Starting certain system services, such as handling image thumbnails in Explorer.

This process is usually safe and part of Windows, and is located at C:\Windows\System32\dllhost.exe.

When should you pay attention to dllhost.exe?

  • If the process consumes a lot of resources. This may indicate a problem with the operation of a specific COM object;
  • If dllhost.exe is located in another directory (for example, C:\Users\UserName* or **C:\Windows\Temp*), it may be a virus or trojan.

How dllhost.exe and COM (Component Object Model) are related

COM (Component Object Model) is a technology from Microsoft for creating software components that can interact with each other regardless of the programming language. 

Where is COM used?

  • OLE (Object Linking and Embedding) is a mechanism in Windows for embedding objects (for example, Excel tables in Word documents);
  • ActiveX is a technology for creating components used in browsers and applications;
  • Windows Shell Extensions – Explorer extensions, such as generating thumbnails of images;
  • DirectX is the Windows graphics platform.

Role of dllhost.exe in COM

When an application requests to work with a COM process that must run separately, Windows launches dllhost.exe and loads the process into it. Using dllhost.exe allows you to:

  • Protect the main application from failures in COM components;
  • Isolate execution of potentially unstable or unsafe COM objects;
  • Allow COM objects to run across different sessions.

If dllhost.exe is in System32, you don’t need to delete it. But if it’s located elsewhere, it might be malware. In that case, terminate the process, delete the file manually, check the registry, and scan the system with an antivirus.

How to remove dllhost.exe

Via Task Manager

  • Open Task Manager (Ctrl + Shift + Esc);
  • Find dllhost.exe in the list of processes;
  • Right click → End process.

Manually remove suspicious dllhost.exe

  • Stop the process via Task Manager (see above);
  • Select dllhost.exe and right-click on it → “Open file location”;
  • Delete the dllhost.exe file and empty the Recycle Bin.

Through antivirus software

  • Use the built-in Windows Defender or antivirus Malwarebytes, Dr.Web CureIt, Kaspersky Virus Removal Tool;
  • Run a full scan and remove any threats found.

Through safe mode

  • Restart your computer in Safe Mode (F8) or use Advanced Boot Options;
  • Please try deleting manually again.

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