I have Windows 7 (64 bit). The version of Java thats installed on my machine is 1.6. 0_20-b02.
I downloaded jai-1_1_3-lib-windows-i586-jdk and tried to install. It fails with a warning that JDK1.3 or higher must be installed. Isnt 1.6 higher than 1.3? Is there a trick in installing JAI1.1.3?
It is higher, and there is no trick. You should be able to just run the exe. If push comes to shove, you can simply download the zip file and place jai_core.jar and jai_codec.jar into Java/jdk1.6.0_20/jrelib/ext/ . This will give all the functionality, but no native acceleration.