open java jnlp

Select the Java folder, (If you do not see Java, go back up one level to the c:/ drive and select Program Files(x86), then select the Java folder. If you do not have a Java folder here, you will want to go to www.java.com and download the latest version before continuing with these steps.)
Double click the latest jre folder (example: jre7, jre1.8_25, etc)
Double click the bin folder Double
click the javaws application Click the Close button JNLP files will now open, by default, with Java Web Start






Reference:
https://blackboard.secure.force.com/btbb_exportarticlepdf?id=kA770000000CbF5CAK