After Creating the Directory Structure we have to first install the Java, because with out JRE , Sun IDM will Not install, For The basic Requirement of Installation of IDM go on previous Post ( Basic Requirement)Here You can Find that How java Has to install and How to set the path of JAVA_HOME and class path inside Environment Variable.Because duraing installation of Sun - IDM it ask of JRE, here i am going to install the JDK 1.7 Version That you can download it from Sun Website