COM Surrogate(dllhost.exe): Disable and Delete Open Files in it

Are you annoyed by a COM Surrogate error, “The action can’t be completed because the file is open in COM Surrogate,” that prevents you from deleting, moving, or editing a file on your computer? Then, you can put your worries aside, as we are here to help you fix this problem in no time. 

While many users confuse COM Surrogate with a virus when it throws a “File in use” error, it is not the case, and these errors are quite simple to fix. If you’re concerned about malware, it’s important to note that legitimate browser COM Surrogate processes should reside in the System32 folder of your Windows directory. 

For added reassurance, you can run a trusted antivirus scan to rule out any threatening issues. Let’s clear the mystery around COM Surrogate and the causes of its file errors before attempting to fix them.

What Is the COM Surrogate

COM Surrogate is an essential Windows component (often dllhost.exe), a legitimate process that hosts crucial software components (COM objects) to use them for other programs, especially for tasks such as file thumbnail generation in File Explorer, preventing crashes by isolating them. 

If an outdated codec or another buggy file previewer crashes, this “sacrificial” process takes down the COM Surrogate (resulting in the COM Surrogate not working error) instead of the entire system to improve stability. 

Moreover, the COM Surrogate errors like “File is open in COM Surrogate” occur because the actual dllhost.exe process gets stuck while processing media or generating thumbnails. Let’s talk more about this in the next section. 

What Causes the COM Surrogate “File Is Open in COM Surrogate” Error

Many factors may be responsible for the COM Surrogate file issues, such as the thumbnail generation getting stuck, File Explorer glitches, security software interference, corrupted thumbnail cache, pressure on the system resources, outdated drivers, and incompatible software. Below are these causes in detail. 

• Thumbnail generation went wrong: When Windows Explorer tries to create a thumbnail preview of high-resolution images or videos, the COM Surrogate may get stuck, resulting in the issue you are experiencing.
• File Explorer issues: COM Surrogate can hold files open for indefinite periods, often during bulk operations (such as copying folders) or a crash, because of a File Explorer glitch.
• Thumbnail cache corruption: The thumbnail databases (thumbs.db files) may build up and become corrupted.
• Third-party software interference: Some third-party applications, such as antivirus software or cloud sync tools, may interfere with the COM Surrogate process.
• System resource overloading: Your CPU may be overloaded with heavy processes, or your RAM may be low, causing the COM Surrogate not to work and file problems.
• Outdated graphics drivers: An outdated graphics driver breaks the communication between your computer and the graphics card, resulting in COM Surrogate errors.

Now that you are familiar with COM Surrogate not working and file errors, let’s help you fix it. 

How to Fix the File Is Open in COM Surrogate and Disable It

The solutions to the COM Surrogate not working problem, including the files open in it, are stopping the COM agent, deleting the thumbnail cache, performing a clean boot, disabling the Data Execution Prevention, turning off hardware graphics acceleration, and the following. 

Note: It is not necessary to try all the solutions below. You can start from the first one and stop when the problem is resolved. 

1. Stop the COM agent process

Ending the COM agent process has helped many users fix the COM Surrogate issue. Hence, below is how to end this process. 

• First, use the combination of Ctrl, Shift, and Esc keys to launch the Task Manager.
• Once the Task Manager appears, navigate to the Details tab.
• Next, locate and right-click on the dllhost.exe process and choose End Task from the on-screen options.
• Lastly, restart your computer to apply the changes.

2. Delete the thumbnail cache

A corrupted thumbnail cache is one of the prime causes of the COM Surrogate delete file error. Hence, you can follow the steps below to clear the thumbnail cache. 

• In the first step, launch File Explorer and go to This PC.
• Next, type :::{645FF040-5081-101B-9F08-00AA002F954E} in the address bar and press Enter to open the Folder Options dialog.
• Now, navigate to the View tab, scroll down, and check Always show icons, never thumbnails.
• In this step, click Apply and OK.
• Lastly, uncheck the box next to Always show icons and apply the changes.

Also know: Fix the Infinite Loop of “Preparing Automatic Repair” on Windows 10

3. Clean boot your computer

Performing a clean boot starts your computer with only the necessary drivers and applications, which may fix the COM Surrogate not working problem. Below is how to proceed with this solution. 

• First, apply the combination of the Windows and R keys to launch the Run utility.
• In this step, type msconfig in the on-screen Run box and press Enter.
• Navigate to the General tab and click Selective startup.
• Now, check the Load system services and Load start items options.
• Next, navigate to the Services tab and click the box next to Hide all Microsoft services.
• Now, check all the on-screen third-party applications and click Disable All to turn off all these services.

• In this step, navigate to the Startup tab and click Open Task Manager.
• Next, right-click each application in the Task Manager and click Disable.
• Lastly, click Apply and OK to save the changes, and restart your computer.

4. Turn off Data Execution Prevention

Data Execution Prevention (DEP) helps prevent damage to your PC. It shuts down a program if the program executes code from memory incorrectly. Hence, disabling DEP can help fix the COM Surrogate file delete issue. However, before following the steps below to perform this action, please remember that disabling DEP globally can make your computer less secure. 

To mitigate this, you can easily re-enable DEP by using the command ‘bcdedit /set {current} nx AlwaysOn’ in the Command Prompt. This reassurance can help you make an informed decision before proceeding.

• To begin the process, apply the Win+R keyboard shortcut to launch the Run utility.
• Next, type cmd in the on-screen Run box and press Ctrl+Shift+Enter to launch the Administrator Command Prompt.
• In the Administrator Command Prompt, copy and paste the following command and press Enter.

BCDEDIT /SET {CURRENT} NX ALWAYSOFF

• Lastly, exit Command Prompt and restart your computer to complete the process.

5. Disable hardware graphics acceleration

Hardware acceleration helps your PC’s hardware perform some actions faster. However, it can also lead to issues such as the COM Surrogate not allowing you to delete, move, or edit files. Hence, you can follow these steps to turn off hardware graphics acceleration. 

• First, use the Windows key and R key combination to launch the Run utility.
• Second, type regedit in the Run box and click OK to open the Registry Editor.
• Next, copy and paste HKEY_CURRENT_USER > Software > Microsoft > Avalon.Graphics in the address bar of the Registry Editor. Before proceeding, it is crucial to back up the registry to avoid accidental issues. This step ensures you can restore your system settings if any changes lead to unintended consequences.
• In this step, locate DisableHWAcceleration on the right side.

Note: If you cannot locate DisableHWAcceleration, right-click an empty area on the right pane, click New > DWORD (32-bit) Value, and name the value DisableHWAcceleration. 

• Next, double-click DisableHWAcceleration and change its value to 1 to turn off Hardware Acceleration on your computer.
• Lastly, click OK to save the changed settings.

6. Delete the interfering application

Sometimes, interference from third-party applications may be responsible for issues like the one you are experiencing. Hence, if you began encountering problems with the COM Surrogate after installing a third-party software, below is how to uninstall it. 

• In the first step, click the Start button to locate the program you wish to delete in the left section list or the tile segment on the right.
• Next, right-click the problematic application and select Uninstall from the on-screen options.
• Lastly, confirm the uninstallation to remove the application.

Also know: Complete Troubleshooter Guide to Fix Windows Update Errors Easily

7. Perform System File Checker (SFC) and DISM scans

If the error occurs because of corrupted files, you can run SFC and DISM scans to find and fix these files. Here is how. 

• Begin by right-clicking on the Start button and selecting Command Prompt (Admin) or Windows Terminal (Admin) from the on-screen menu.
• In the Administrator Command Prompt or Windows Terminal, copy and paste the following commands one by one and press Enter after each of these commands.

sfc /scannow

DISM /online /Cleanup-Image /ScanHealth

DISM /online /Cleanup-Image /RestoreHealth

• Lastly, exit Command Prompt or Windows Terminal and restart your computer to complete the system file repair.

8. Update your graphics driver

The graphics card driver translates your instructions into the language your graphics card understands, and its response to the language your computer understands for perfect execution. If the driver is outdated, this communication breaks, leading to problems like the one you are going through. Thus, you can follow the steps below to update your graphics driver. 

• First, right-click the Start button and choose Device Manager from the on-screen options.

• Second, double-click on the Display Adapters category in the Device Manager to expand it.
• Next, right-click your graphics card and choose Update Driver from the on-screen options.
• In this step, click Search automatically for drivers.
• Next, follow the on-screen instructions to complete the driver download and installation.
• Lastly, allow your computer to restart for the new graphics driver to take effect.

COM Surrogate Not Working and File Deletion Issue Fixed

The above-explained fixes help you solve the COM Surrogate problems, such as the COM Surrogate not letting you move, edit, or delete files. You can execute these solutions sequentially until the problem is resolved. 

However, if you have any confusion or questions about this article, feel free to reach out through the comments section. You can also share your feedback or suggestions, if any, in the comments. If you find the steps overwhelming or need further assistance, consider seeking help from a trusted friend or a local technician. And, for more helpful tech guides delivered to your mailbox for free, subscribe to our newsletter.