Sorry, I am not clear what you asking but try these things.
Two things..
1st : open the task manager and go to process and see if java.exe is
running. if yes then some java program  is running.

2nd
Try to compile a very java program. ( Assume, you have j2sdk install )
do something like this
>javac HelloWorld.java ( Assume you have HelloWorld.java file )
Now, if ou get an execption then do

>set CLASSPATH=;%CLASSPATH%

This command basically set the environment varaible. But, when you
close the cmd window then this setting will go away. I would say set
these settings in Environment Variable so this way you do not need to
set this path everytime.

if you dont know how to install j2sdk then please send me a mail and i
will send you a link.