Hello!
I have been attempting to download forge 1.7.10 for a few days now. When I open it, it flashes up with a command prompt-esque window for about 1 nanosecond which then disappears. When attempting to open with, 2 versions of the Java Runtime Environment appear. Neither works. Here is a video of what it looks like:
I have a windows 10 computer provided by my school. My previous computer was the exact same model, also provided by my school, ran the forge installer and mods (with some pretty significant monkeying around - I was making my own modpack) with very few issues. I think the issue started when I first installed forge on this computer. I forgot that I needed java to run the .jar file and accidentally opened it with a pdf viewer. I installed Java, which didn't appear in the list of programs for so reason, so I navigated directly to the bin file and use the java.exe there. I have learned I should not have done that. Now, like shown above, I have 2 versions of the runtime environment that appear in the open with list and for some reason it wants to run it with the java control panel by default. A list of things I have already tried:
Uninstalling and reinstalling Java (jre 8).
Uninstalling and reinstalling the forge installer.
Uninstalling and reinstalling Minecraft altogether, including the launcher.
Running through command prompt.
Installing JDK 8. This, for some reason, does not appear on the open with list at all.
Monkeying around with the firewall. For some reason, Java is not even present on the list of applications. I even turned off the firewall entirely.