I downgraded java 1.7 from 1.8, but I still see 1.8 when I do java -version. I changed the path and also made JAVA_HOME changed for 1.7 as
JAVA_HOME: C:\Program Files (x86)\Java\jdk1.7.0_79
PATH: C:\Program Files(x86)\Java\jdk1.7.0_79\bin
For some reason I also have this in my path: C:\ProgramData\Oracle\Java\javapath, which I believe keeps this 1.8 version. When I take off this from the path, I get this message: C:\Program Files\Java\jre7\lib\amd64\jvm.cfg. I don't know what's going on. Any suggestion would be very helpful.
TRY DOING THE FOLLOWING:
Type "regedit" from startup menu. Take a back up if you are a novice.
Go to "HKEY_LOCAL_MACHINE->SOFTWARE->JavaSoft->Java Runtime Environment"
Double click on "CurrentVersion" on the right side of the panel
Change version to "1.7".
If you have "C:\ProgramData\Oracle\Java\javapath" in your path variable . Then open the
location and make sure the java.exe file points to respective 1.7 directory.
If you have "C:\ProgramData\Oracle\Java\javapath" in your path variable, bring your JAVA_HOME/bin path before it.
Ex: C:\Program Files(x86)\Java\jdk1.7.0_79\bin;C:\ProgramData\Oracle\Java\javapath.
I faced the similar issue and was not able to downgrade the java version from 1.8 to 1.7.
close your MS-DOS and open a new MS-DOS window. try again.
来源：https://stackoverflow.com/questions/32406548/i-still-see-java-1-8-when-i-am-doing-java-version-after-downgrading-to-1-7