The genuine ShellExt.dll file is a software component of Microsoft File Explorer by Microsoft Corporation.
"ShellExt.dll" is a name often used by multiple software publishers, including Microsoft, for a Dynamic Link Library (.DLL) file that is a "shell extension". The "Windows shell" collectively describes multiple user interfaces in the Microsoft Windows OS performed by File Explorer: the desktop icons, the Start Menu, the Taskbar, and the Control Panel, as well as Windows Explorer itself. A "shell extension" is a .NET assembly that runs under the control of the .NET Common Language Runtime (CLR). At least fourteen different uses of shell extensions are recognized, including adding options to context (right-click) menus, handling drag-and-drop of objects, and copying to the clipboard. Microsoft's "shellext.dll" belongs to its Security Client, a component of Security Essentials, (under Windows XP, Vista, and 7), Windows Defender, (Win8/8.1/10), or Endpoint Security for managed enterprise-owned computers. Other software using "shellext.dll" includes Lavasoft's AdAware and HP CloudDrive.
ShellExt stands for Microsoft Windows Shell Extension
ShellExt.dll is a Windows DLL file. DLL is the abbreviation for Dynamic Link Library. DLL files are needed by programs or web browser extensions, because they contain program code, data, and resources.The following information can help you determine if ShellExt.dll is a Windows system file or if it belongs to an application that you can trust.
Click to Run a Free Scan for ShellExt.dll related errors
ShellExt.dll file information
The process known as Microsoft Security Client Shell Extension or ShellExt Dynamic Link Library or Shell Extension or Agent Ransack Shell Extensions belongs to software Microsoft Security Client or HP CloudDrive or ESET Smart Security or Microsoft Security Essentials or Agent Ransack (version 2010) by Microsoft (www.microsoft.com) or Versionate or ESET (www.eset.com) or Mythicsoft.
Description: ShellExt.dll is not essential for the Windows OS and causes relatively few problems. ShellExt.dll is located in a subfolder of "C:\Program Files (x86)"—in most cases C:\Program Files (x86)\Microsoft Security Client\ or C:\Program Files (x86)\ESET\ESET NOD32 Antivirus\.Known file sizes on Windows 10/11/7 are 272,464bytes (17% of all occurrences), 200,704bytes and 19 more variants. 
A .dll file (Dynamic Link Library) is a special type of Windows program containing functions that other programs can call. This .dll file can be injected to all running processes and can change or manipulate their behavior.The program has no visible window. The file is not a Windows core file. There is no detailed description of this service. It can change the behavior of other programs or manipulate other programs. The ShellExt.dll file is digitally signed. You can uninstall this program in the Control Panel.ShellExt.dll is able to monitor applications, record keyboard and mouse inputs and hide itself.Therefore the technical security rating is 50% dangerous, however you should also read the user reviews.
Uninstalling this variant:In the event of any problems with ShellExt.dll, you can do the following:
- ask the developer, www.microsoft.com, for support
- uninstall the program using the Control Panel ⇒ UninstallaProgram ⇒ Microsoft Security Client or HP CloudDrive
Recommended: Identify ShellExt.dll related errors
Important: Some malware camouflages itself as ShellExt.dll, particularly when located in the C:\Windows or C:\Windows\System32 folder. Therefore, you should check the ShellExt.dll process on your PC to see if it is a threat. We recommend SecurityTaskManager for verifying your computer's security. This was one of the Top Download Picks of The Washington Post and PCWorld.
Best practices for resolving ShellExt issues
A clean and tidy computer is the key requirement for avoiding problems with ShellExt. 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.
To help you analyze the ShellExt.dll process on your computer, the following programs have proven to be helpful: ASecurity Task Manager displays all running Windows tasks, including embedded hidden processes, such as keyboard and browser monitoring or Autostart entries. A unique security risk rating indicates the likelihood of the process being potential spyware, malware or a Trojan. BMalwarebytes Anti-Malware detects and removes sleeping spyware, adware, Trojans, keyloggers, malware and trackers from your hard drive.
Other processes
stc.dll slimjet.exe cpuz146_x64.sys ShellExt.dll orangeinstaller.exe mbae64.sys hotkeyservice.exe ubarservice.exe regorganizer.exe tosbtmng.exe aesm_service.exe [all]
