How program should I use to open .jar files as installers?

[Sampa]

How program should I use to open .jar files as installers?

[Camacha]

.jar are Java files. Without any extra information what you are doing, trying to do and have tried it is hard to help though. Try installing Java, that's your best bet.

[Sampa]

Yeah, I was being vague partly because I am unsure of what information is truly valid. But I am trying to install the program: Forge so I can install some mods onto Minecraft

[Brethern]

Yeah, I was being vague partly because I am unsure of what information is truly valid. But I am trying to install the program: Forge so I can install some mods onto Minecraft

Or you could just get a curse account and use the new curse launcher to make the process 99% fool proof.