Minecraft Forge installer as a Wordpad file and not as an application?

I want to download Minecraft Forge to get shaders. Everything went great on my old PC. But on my new one, as soon as I download the Forge Installer, it's a Wordpad file.

In what way? Are you sure you downloaded this from the official site?
Could you send a screenshot of the file?

Yes it was downloaded from the correct page. It is also the correct file, however not as an application but as a Wordpad. I've read that it fixes the error if you run the file with Java, but that's not an option for me

Do you have Java installed?

Right click> Open with…> Java

If Java isn't there, you'll need to install Java:

https://www.java.com/.../download/

Yes, I have but somehow when I enter Java in the search bar I only see "Configure Java". Usually Java is also displayed at the bottom right next to the arrow next to the apps in the background, but somehow not

Can you send a screenshot?

I have installed Java, but it is not displayed when I open with…

You can also click "Use other app" and then select the path and select javaw.exe at the end.