Downloads won't go through properly

Hello. I'm new to OpenBVE and this forum.

I've encountered a problem when I try to download most things related to Open BVE. When I get the download, it appears with the blank paper icon, and it will always say it does "Not have an app associated with it for performing the action", with the action being the OpenBVE download. By the way, I was downloading the Developers Tools, just if something comes to mind. Here are some pictures if this is familiar: 

As I said, I'm new to this BVE thing. Do I need a certain application to download things? Please help me with this!

Currently, the OpenBVE Developer's Tools are distributed with the main program of OpenBVE.
Therefore, no additional downloads are required.
They are located in the installation directory of the main program.
Please check it.

Also, .7z is a data compression format.
You need an archiver such as 7-Zip as it cannot be unzipped with standard Windows features.

I've got Train editor, so I should have the developer's tools installed. 
I've just installed 7-zip so anything I download should go through, right?

The information on the official homepage remained old.
The information is now updated.
https://openbve-project.net/creating-addons/

As I wrote in the previous post, developerTools_1.4.4.0.7z you downloaded is a compressed file that contains older developer tools.
That tool is currently unavailable.

If you have the main program of OpenBVE installed, you will find the developer tools in the installation folder.
If you have not installed it, install it.

I have installed OpenBVE.

This also doesn't work with other downloads. Anything to fix it?

Open the folder where OpenBVE is installed.
Developer tools exist in that folder.

The default installation folder exists in the following path:
64bit OS:    C:\Program Files (x86)\openBVE
32bit OS:    C:\Program Files\openBVE