The Java Runtime Environment (JRE) provides the necessary libraries and components required to run Java applications. Certain Crossfire tools and utilities depend on Java for execution, particularly those involving map editing, asset processing, or legacy tooling.

This guide walks through installing a JRE on Windows 11.

• Windows 11 (64-bit recommended)
• Administrator privileges
• Internet connection

1. Navigate to a trusted Java distribution provider:
   • https://adoptium.net/
   • https://www.oracle.com/java/technologies/downloads/
2. Select:
   • Version: Latest LTS (e.g., Java 17 or newer)
   • Package Type: JRE (or JDK if JRE-only is unavailable)
   • OS: Windows x64
3. Download the installer (.msi or .exe)

1. Locate the downloaded file.
2. Double-click to launch the installer.
3. If prompted by User Account Control (UAC), click Yes.

1. Click Next on the welcome screen.
2. Choose installation directory (default is recommended).
3. Click Next to begin installation.
4. Wait for installation to complete.
5. Click Finish.

1. Open Command Prompt:
   • Press `Win + R`, type `cmd`, press Enter.
2. Run the following command:

java -version

1. Expected output (example):

openjdk version "17.0.x" 202x-xx-xx
OpenJDK Runtime Environment (build 17.0.x+xx)
OpenJDK 64-Bit Server VM (build 17.0.x+xx, mixed mode)

Some tools may require Java to be explicitly available in the system PATH.

1. Open System Properties:
   • Press `Win + R`, type `sysdm.cpl`, press Enter.
2. Go to Advanced tab → click Environment Variables.
3. Under System variables, find `Path`, then click Edit.
4. Add the path to the JRE `bin` directory, e.g.:

C:\Program Files\Java\jre-17\bin

1. Click OK to save changes.

1. Open a new Command Prompt.
2. Run:

java -version

1. If the version displays correctly, PATH is configured.

• Some legacy Crossfire tools may expect Java 8 compatibility.
• Newer tools generally work with Java 11+ or Java 17 LTS.
• If multiple Java versions are installed, ensure the correct version is prioritized in PATH.
• For development work, installing a full JDK is recommended instead of JRE.