Just type jdk-21_windows-x64_bin.exe /s in the command prompt. Visit the Java Downloads page. Click the Windows tab. Choose and download your Java version. There's currently JDK 21 and JDK 17 Method #01: Double-click to run. After installing JRE or JDK, you’ll have the means to run a jar file natively on your PC. You should see your jar files in Java executable form right off the bat. If you don’t, you’ll need to right-click on the jar file and choose to run it using the OpenJDK platform library or similar. The above instructions would still remain same. Open the control panel and type envir in search bar. Click on edit the system environment variables. Click on environment variables in the advanced system properties. Click on path mentioned in user variables. Edit the path, and click new and paste the path of java jdk. From the Command Prompt, navigate to the directory containing your .java files, say C:\introcs\hello, by typing the cd command below. C:\Users\username> cd c:\introcs\hello C:\introcs\hello\> Assuming the file, say HelloWorld.java , is in the current working directory, type the javac command in boldface below to compile it. z3GUW.