Installing the standalone version is easy:

1. Download and install the Java Development Kit (JDK) from http://java.sun.com/j2se/1.4.2/download.html. You want the J2SE SDK version without the Sun Java System Application Server.
2. Set the JAVA_HOME variable to where you installed Java. If you are running windows, steps on how to do this can be found here
3. Unzip the standalone version into a directory. It does not matter where you put it, but you need to remember where it is. This directory is called the 'confluence install directory' in the rest of the instructions.
4. Ensure that you do not have the CATALINA_HOME environment variable specified or pointing to a previously installed instance of Tomcat. The confluence standalone instance runs within a bundled tomcat instance, and having CATALINA_HOME specified in the environment will confuse the tomcat startup scripts.
5. Edit the confluence-init.properties file in the confluence\WEB-INF\classes directory which you can find under the confluence install directory, and set the confluence.home property to a directory of your choice. The line that you need to change in the confluence-init.properties file looks like #confluence.home=/tmp/confluence. You need to change it to confluence.home=<your confluence home location>. For example you might choose c:/confluencedata as your confluence.home directory, so you'd change that line to confluence.home=c:/confluencedata. Don't forget to remove the leading '#' character. This directory is where Confluence will store it's configuration information, indexes and attachments, so the user running the server must have write access to this directory.
6. Run bin/startup.sh (*nix) or bin\startup.bat (Windows). Check that there are no errors on the console. See Troubleshooting & Technical Support if you see any errors
7. Point your browser at http://localhost:8080/. You should see the Confluence Setup Wizard!