i find this guide for helping me setting Java_Home http://javarevisited.blogspot.it/2012/02/how-to-set-javahome-environment-in.html

but i really cant understand what i must do on step 5 .if anyone could explain what and where i must do would be nice.

Start Button 

 

My Computer 

Properties 

 

Advanced System Settings 

 

Enviroment Variables Image (It's too big)

 

Then create a new one like  this

 

In this image, in the first form you should type JAVA_HOME And in the second you should add the path of your jdk bin folder (like C:\Program Files\Java\jdk1.7.0_55\bin)

 

Then press Ok

 

Ok again, and you are done!

i had already done this but i thought that i had something more ... thanks for help