Windows has blocked this software because it cannot verify the publisher

Error “Windows has blocked this software because it cannot verify the publisher” when you try to access a website which tries to install addons or run executables like installation CAB files.

By default Internet Explorer disable running unsigned ActiveX controls. Unsigned ActiveX controls are programs that tries to execute a command on your PC, like CAB install files or a ZIP file which do not have a digital signature.

Install Video Tutorial:

This is an important security measure on the Internet Explorer browser, if you are sure that the website is a trusted one then you can temporarily disable this security feature to get the website run the required ActiveX and later on re-enable the security.


Click on Tools,in the dropdown Box Click on Internet option, Click on the Security Tab, Then on Custom Level.

Under ActiveX controls and Plug-ins ensure the following are set to:

  1. (Disable) Allow previously unused ActiveX controls to run without prompt
  2. (Enabled) Run ActiveX Controls and plug-ins
  3. (Enabled) Script ActiveX controls marked as safe for scripting*
  4. (Enabled) Download Signed ActiveX Controls – *Some cases just by Enabling Download Signed ActiveX Control is good enough*
  5. Download unsigned ActiveX Control – (Prompt)
  6. Initialize and script ActiveX controls not mark as safe – (Prompt)
  7. Click OK and Apply and OK. to restart the browser.

You should now be able to run the ActiveX control on the website. As I said earlier, please ensure that you have the above to what it was before.

To Restore Internet Explorer to Default configuration Follow these steps:

  1. Open internet explorer, click ToolsInternet options.
  2. Click the Security tabReset all zones to default level


I started this tech blog back in 2011 as a place to write down processes I took to fix my client systems and network. Now I write some tips and tricks to help others with the tech issues that one might encounter.

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