Install Java (JDK) on Windows

Why Java on Windows

Java runs a huge number of programs and servers, such as Tomcat, Jenkins and Minecraft-like tools. To develop in Java, or to run many server apps, you need a JDK (Java Development Kit).

Step 1: Download the JDK

Open the Oracle website (or use a free OpenJDK build such as Eclipse Temurin) and download the Windows x64 Installer of the JDK version you need. Long-term support versions such as 17 and 21 are good choices.

Step 2: Run the installer

Open the downloaded .exe (or .msi) file.

Click Next.

Step 3: Choose the install location

The default folder is fine, for example C:\Program Files\Java\jdk-21.

Step 4: Install

Click Install, wait, and click Close.

Step 5: Check Java

Open a new Command Prompt:

java -version
javac -version

If you see the version, Java works.

Set JAVA_HOME and the PATH (if needed)

Some installers set the PATH by themselves. If java is not found:

1. Search for environment variables and open Edit the system environment variables. Click Environment Variables.
2. Click New under System variables. Name it JAVA_HOME and give the JDK folder as the value, for example C:\Program Files\Java\jdk-21.
3. Select Path, click Edit, click New and add %JAVA_HOME%\bin.
4. Click OK in all windows and open a new Command Prompt.

A first program

Create Hello.java:

public class Hello {
    public static void main(String[] args) {
        System.out.println("Hello, Java!");
    }
}

Compile and run:

javac Hello.java
java Hello

Quick recap

• Download and run the JDK installer.
• Check with java -version.
• Set JAVA_HOME and the PATH if the command is not found.