I can\'t open or run my .jar file.
I just installed java, but I tried to open the .jar with other programs first, so the double-click defaults to something else and
An easy way to execute .jar files is to create a batch file.
Let's say you placed your jar file on your Desktop;
@echo OFF
java -jar C:\Users\YourName\Desktop\myjar.jar
Copy this code to a .txt file, modify "YourName" and save as "myjar.bat". Then whenever you double click, the jar file will be executed. Hope this helps.