I need help

I’m new with Asterisk.I want to create an application in Java that interacts with Asterisk and I want to know if I need to Install Linux or if just with my Windows Installation and the JVM(Java Virtual Machine) is enough.

I am assuming that you have Asterisk installed on a linux server (personally I wouldn’t bother installing Asterisk on Windows).
Then you can use fastAGI (Asterisk Gateway Interface) with the Asterisk-Java framework. This will work through a TCP connection from Asterisk to your Windows server running the Java app.
You would configure an extension in Asterisk to something like:

exten => 1234,1,AGI(agi://youJavaServerIP/somename)

Asterisk will open a TCP connection to port 4573 on your Windows server and you can then handle the call.