This error happens because Microsoft has implemented a new security feature for Windows 10 that blocks any app that does not have a 2016 security signature.
To get past this error you need to do the following:
Launch Start Menu, search and select Command Prompt. Then right-click on it and choose Run as Administrator from the context menu.
Type the following command without quotes at the Command Prompt and then hit Enter: "net user administrator /active:yes". You should see the message saying "command completed successfully".
Launch Start Menu once again and right-click on user-account title at the top-left of the screen. Then click Sign-out.
At the login screen, log into the Administrator account and you will return to the Desktop of that user profile.
Locate and run the .exe file for the program which you want to install.
As you have already logged into the Administrator account, the Smartscreen protection will be disabled and the installation should complete successfully.
After you have completed the installation, just log back into your regular account after logging out of the Admin account.