Hello there, Im on Site 27 and i have done what the Book said. I downloaded the JDK and installed it. After that i put in the shell : javac -version but i was getting the error sh: javac: not found. After that i was going on this site to search if People had experienced the same problem. I saw someone said i should remove everything (that has to do with java) and reinstall it. I did that but still no success. I really need some help here.