What is coIEPlg.dll?

CoIEPlg.dll is a browser extension for Internet Explorer. This add-on enables several additional functions for Internet Explorer. You can disable it through the Extras menu (key combination Alt + X) under Manage Add-ons. The following paragraph provides more information about coIEPlugIn.

Click to Run a Free Scan for coIEPlg.dll related errors

CoIEPlg.dll file information

The process known as coIEPlugIn

belongs to software Norton Internet Security (version 2006) or Norton Confidential or Norton Identity Safe or Norton Security Suite or Norton Confidential Core or Norton 360 Premier Edition or Norton Safe Web Lite or Norton Security with Backup or Norton 360

by Symantec (

Description: CoIEPlg.dll is not essential for Windows and will often cause problems. The coIEPlg.dll file is located in a subfolder of "C:\Program Files". Known file sizes on Windows 10/8/7/XP are 436,152 bytes (12% of all occurrences), 509,776 bytes and 43 more variants. 
This .dll file is a Browser Helper Object (BHO) that runs automatically every time you start your web browser. BHOs are not stopped by personal firewalls, because they are identified by the firewall as part of the browser itself. BHOs are often used by adware and spyware. IDs used by this BHO include 602ADB0E-4AFF-4217-8AA1-95DAC4DFA408 or F0DA78E9-6B60-42fb-BC26-EF2CFB8C8FF3 or B8E07826-0971-4f16-B133-047B88034E89 or AB4C7833-A6EC-433f-B9FE-6B14B1A2F836. The program has no visible window. CoIEPlg.dll is a Verisign signed file. The file is able to change the behavior of, or monitor Internet Explorer. CoIEPlg.dll is certified by a trustworthy company. CoIEPlg.dll is not a Windows system file. Therefore the technical security rating is 33% dangerous, however you should also read the user reviews.

Uninstalling this variant: If you still experience problems with coIEPlg.dll, you can do the following:
  • get help from the software vendor Symantec
  • uninstall the associated program (Start > Control Panel > Uninstall a Program > Norton Internet Security or Norton 360)

Recommended: Identify coIEPlg.dll related errors

If coIEPlg.dll is located in a subfolder of "C:\Program Files\Common Files", the security rating is 29% dangerous. The file size is 357,744 bytes (41% of all occurrences), 349,552 bytes or 316,784 bytes. The program has no visible window. CoIEPlg.dll is a Verisign signed file. CoIEPlg.dll is able to monitor web browsers. The file has a digital signature. The coIEPlg.dll file is not a Windows core file.

Uninstalling this variant: If you still experience problems with coIEPlg.dll, you can uninstall the associated program (Start > Control Panel > Uninstall a Program > Norton Confidential Core or ccCommon).

Important: Some malware camouflages itself as coIEPlg.dll. Therefore, you should check the coIEPlg.dll process on your PC to see if it is a threat. If coIEPlugIn has changed your browser's search engine and start page, you can recover your browser's default settings as follows:

Reset default browser settings for Internet-Explorer ▾
  1. In Internet Explorer, press the key combination Alt + X to open the Tools menu.
  2. Click Internet options.
  3. Click the Advanced tab.
  4. Click the Reset... button.
  5. Enable the Delete personal settings option.
This will reset your Internet Explorer to its default settings. Your browser will start with the familiar start page and search engine—without popups, ads, cookies, but all browser add-ons are deleted too [1]. Make cleaning up your browser and your computer simpler and safer with Security Task Manager.


User Comments

Norton Internet Security 2010
Norton system file
is Norton signed therefore should be cosha

Rating chart

Summary: Average user rating of coIEPlg.dll: based on 8 votes with 3 user comments. 3 users think coIEPlg.dll is essential for Windows or an installed application. 3 users think it's neither essential nor dangerous. 2 users think coIEPlg.dll is dangerous and recommend removing it.

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Best practices for resolving coIEPlg issues

The following programs have also been shown useful for a deeper analysis: Security Task Manager examines the active coIEPlg process on your computer and clearly tells you what it is doing. Malwarebytes' well-known anti-malware tool tells you if the coIEPlg.dll on your computer displays annoying ads, slowing it down. This type of unwanted adware program is not considered by some antivirus software to be a virus and is therefore not marked for cleanup.

A clean and tidy computer is the key requirement for avoiding PC trouble. This means running a scan for malware, cleaning your hard drive using cleanmgr and sfc /scannow, uninstalling programs that you no longer need, checking for Autostart programs (using msconfig) and enabling Windows' Automatic Update. Always remember to perform periodic backups, or at least to set restore points.

Should you experience an actual problem, try to recall the last thing you did, or the last thing you installed before the problem appeared for the first time. Use the resmon command to identify the processes that are causing your problem. Even for serious problems, rather than reinstalling Windows, you are better off repairing of your installation or, for Windows 8 and later versions, executing the DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.

Other processes

coIEPlg.dll [all]