Java Multiple Installations – Change Active Java Runtime With Minimal Effort

This answer explains stuff with examples.   ME NO ₩OᴚDS MUCH ᴯᵁᵍᴬ ᴯᵁᵍᴬ 🍗

👉 Better Use the 8.3 directory-format. In fact No spaces, ever. 👍

JAVA_HOME – your JDK folder
C:\Program Files\Java\jdk1.6.0_45 == C:\PROGRA~1\Java\JDK16~1.0_4
C:\Program Files\Java\jdk1.7.0_71 == C:\PROGRA~1\Java\JDK17~1.0_7
C:\Program Files\Java\jdk1.8.0_25 == C:\PROGRA~1\Java\JDK18~1.0_2
C:\Program Files\Java\jdk1.9.0 == C:\PROGRA~1\Java\JDK19~1.0

JRE_HOME
C:\Program Files\Java\jre6 == C:\PROGRA~1\Java\jre6
C:\Program Files\Java\jre7 == C:\PROGRA~1\Java\jre7
C:\Program Files\Java\jre1.8.0_25 == C:\PROGRA~1\Java\JRE18~1.0_2
C:\Program Files\Java\jre1.9.0 == C:\PROGRA~1\Java\JRE19~1.0

Addition to PATH – best practice!
USE [WINDOWS]+[R] !!! ➩ C:\Windows\system32\systempropertiesadvanced.exe
add ;C:\ProgramData\Oracle\Java\javapath; to the end of PATH (System Variables not User Variables).

  • click OK👆, explore to C:\ProgramData\Oracle\Java\ and rename javapath folder (from C:\ProgramData\Oracle\Java\javapath\) to javapath_old.
  • create new folder named javapath.
  • start CMD and browse into (the now empty) C:\ProgramData\Oracle\Java\javapath\.
  • run to create symbolic links:
    ln -s "C:\Program Files\Java\jre7\bin\java.exe" java.exe
    ln -s "C:\Program Files\Java\jre7\bin\javaw.exe" javaw.exe
    ln -s "C:\Program Files\Java\jre7\bin\javaws.exe" javaws.exe
  • *done with PATH and *_HOME stuff (that’s for kids 🎉), now **let’s have fun with Windows Registry..*
    ➃ open up you prefered registry editor (Registry Workshop is the best), browse HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Development Kit notice all installed versions are shown as keys, double click CurrentVersion (REG_SZ value) and modify its data to your prefered SDK version, mine is 1.7 (For Android Studio)

➄ do the same for HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment (with CurrentVersion..)

➅ close down java-based programs such as eclipse or IntelliJ ,
Open up task-manager- processes tab, look for explorer.exe, cmd.exe and java(*something*).exe programs, right-click end them (no “End Process-Tree”!), click FileNew Task➩enter explorer.exe
.

🌟 The changes you’ve done above were applied successfully🌟

No need to reboot, No need to log-off/on again .

also published at stackoverflow