will u please tell me how install java software

Go to Oracle web site and Choose JDK7 update21.

Download the latest version of the Java JDK from () for windows Double-click on the install file and it should open an installer Click next, then accept the license and flow the instruction on the wizard , accept default settings and finish settings.
Open the properties of "My Computer" by either right-clicking the icon on the desktop or right-clicking Start > My Computer > Advanced > Environment Variables Double-click on the "Path" variable on either of the option boxes.
Careful not to delete anything in this box.
At the end of the text box, add a semi-colon if there is not one already, and add the path to your java installation Click "Apply" and "OK" to all the windows you have just opened Open the command prompt and type "javac" hit enter