Find these two files in the tomcat bin directory, right-click to edit:
Add two sentences under the sentence rem Guess CATALINA_HOME if not defined
set JAVA_HOME=C:\Program Files\Java\jdk1.7.0_79 //The absolute path where your jdk is stored
set SET TOMCAT_HOME=C:\apache-tomcat-8.0.50 //Your tomcat decompression path
It's ok to try again