1.Open weka.jar & click on Explorer :
A new window opens "WEKA Knowledge Explorer" with six tabs:
a.Preprocess: to select a file, inspect and prepare the data.
b.Classify: To CHOOSE, implement and test different classification algorithms: in our case this would be a decision tree algorithm.
c.Cluster: To Choose, apply and test the segmentation algorithms.
d.Associate: To apply the algorithm for generating association rules.
e.Select Attributes: To choose the most promising attributes.
f.Visualize: to display (in two dimensions) certain attributes in other functions.