You may get this error when downloading or installing one of the executable (.exe) or library (.dll) files for ADE that you have downloaded.  The operating system may block access to the file(s) on the basis that they have come from an unknown source and be a security risk.  You will need to unblock the file before it can be accessed by ADE.  To do this navigate to the file, right click on it and select Properties

Look at the attributes section.  If it looks like this:

Then you can see that it has been blocked by the system and you need to click 'Unblock'.  This should clear the error message and ADE should run normally.