java -version and javac -version showing different versions

I have java 7 and java 8 both installed on my windows system under C:\Program Files\Java

In the environment’s path I specified the path of java 7 like this.

%JAVA_HOME%/bin where JAVA_HOME = C:\Program Files\Java\jdk1.7.0_17

But when I type javac -version it shows javac 1.7.0_17 which makes sense

but when I do java -version it shows

java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b132)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b70, mixed mode)

Any idea what may be the problem here?

And one more thing echo %PATH% has only one occurence of JDK that is for java 7 and no occurence for JRE found in it.