Most antivirus programs classify APIHelper.dll as a harmful extension to Internet Explorer: e.g. ADW_Adstantinko (detected by TrendMicro), and not-a-virus:AdWare.Win32.BHO.bera (detected by Kaspersky). Add-ons like this can display ads, slow down your computer and cause various other errors. If you can't remember installing the associated APIHelper Module software, it's no surprise. In most cases, this kind of adware is installed on the side when you install a freeware product like a Youtube Downloader or a PDF Converter. In the following selection, you can read more about APIHelper Module and how to get rid of it.
Description: APIHelper.dll is not essential for Windows and will often cause problems. APIHelper.dll is located in a subfolder of the user's profile folder or sometimes in a subfolder of "C:\Program Files"—common is C:\Users\USERNAME\AppData\Local\Microsoft\Internet Explorer\Extensions\ or C:\Users\USERNAME\Local Settings\Application Data\Microsoft\Internet Explorer\Extensions\.
Known file sizes on Windows 10/8/7/XP are 199,168 bytes (54% of all occurrences) or 242,688 bytes.
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 0CB66BA8-5E1F-4963-93D1-E1D6B78FE9A2. There is no file information. The program has no visible window. APIHelper.dll is able to monitor web browsers. APIHelper.dll is not a Windows system file. Therefore the technical security rating is 64% dangerous.
Recommended: Identify APIHelper.dll related errors
Important: You should check the APIHelper.dll process on your PC to see if it is a threat. If APIHelper Module 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 ▾
The following programs have also been shown useful for a deeper analysis: ASecurity Task Manager examines the active APIHelper process on your computer and clearly tells you what it is doing. Malwarebytes' well-known Banti-malware tool tells you if the APIHelper.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 1cleanmgr and 2sfc /scannow, 3uninstalling programs that you no longer need, checking for Autostart programs (using 4msconfig) and enabling Windows' 5Automatic 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 6resmon 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 7DISM.exe /Online /Cleanup-image /Restorehealth command. This allows you to repair the operating system without losing data.