Java version shows 7 and Java version shows 8 in windows?

Question

I am really frustrated to see following behavior and not sure yet after research how to fixed this. I've two separate projects one works only on Java 7 (can't update to Java 8) and another project works on Java 8 (can't downgrade to 7). So I've both Java 7 and 8 installed on my windows machine.

So, I am seeing following behavior constantly. Currently I am on Java 8 and would like switch back Java 7, so I changed environment variable JAVA_HOME and PATH to point to Java 7, but when I verify through CMD, it shows me following.

C:\>java -version
java version "1.8.0_45"
Java(TM) SE Runtime Environment (build 1.8.0_45-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

C:\>javac -version
javac 1.7.0_71

I can't use above combination, neither projects works for me. So I always need to uninstalled Java 8 and then only I can point to Java 7. Also if I want to move back to Java 8 (again installed Java 8), then it shows me following combination. How to fixed this error on Windows? As uninstalling the JDK every time is not the solution. Please help me.

C:\>java -version
java version "1.7.0_71"
Java(TM) SE Runtime Environment (build 1.7.0_71-b15)
Java HotSpot(TM) 64-Bit Server VM (build 25.45-b02, mixed mode)

C:\>javac -version
javac 1.8.0_45

Answer 1

java.exe, the Java runtime, also installs in c:\windows or c:\windows\system32 (can't remember, I'm on a Mac now).

So even if your PATH contains the bin directory of JDK, if c:\windows (or c:\windows\system32) comes before JDK\bin in the PATH, the version in c:\windows (or c:\windows\system32) is the one that is used.

Just make sure the JDK is first in the PATH, or at least before c:\windows (or c:\windows\system32).