Download the JAI library from: http://download.java.net/media/jai/builds/release/1_1_3/

If you're an end-user, download: jai-1_1_3-lib-windows-i586-jre.exe (or the equivalent JRE file for your platform).

If you're a developer, download: jai-1_1_3-lib-windows-i586-jdk.exe (or the equivalent JDK file for your platform) and also see the instructions found at: http://download.java.net/media/jai/builds/release/1_1_3/INSTALL.html