Windows Has Blocked This Software Because It Can't Verify The Publisher

A while ago I tried to view CCTV connected to my network using Internet explorer. A problem occurred when it tried to install the .cab file stored from the DVR. A message like this shown on my browser.

Figure 1. Internet Explorer. ActiveX blocked

I clicked install hoping that the issue will be resolved but then this Security Warning message dialogue appeared.

Figure 2. Internet Explorer Security Warning

It's obvious that the problem came from the browser, not the DVR. So I tried to look into internet option menu in Internet Explorer. Here's what I did to get rid this Security Warning.

1. Go to Security Tab in Internet Option. Then click on custom level button.

   

   Figure 3. Security Tab

2. Click enabled (not secure) radio button in Download unsigned ActiveX controls (not secure) option.

   

   Figure 4. Unsigned ActiveX 

3. Refresh browser or reconnect to CCTV's IP to reinstall the software.
4. When you're done and the software has been installed and run smoothly, I suggest you to restore the "Download unsigned ActiveX controls (not secure) option" (Figure 4) to "Disable" for security reason.