diff -r 47b05aef20b3 launcher/launchers.bat.in
--- a/launcher/launchers.bat.in	Thu May 18 09:42:16 2017 +0200
+++ b/launcher/launchers.bat.in	Thu May 18 07:26:21 2017 -0700
@@ -12,8 +12,21 @@
 
 rem warning for linux users: when you put VAR="value" also quotes are stored in VAR!
 rem maybe set "VAR=value" is working better?
-set INST_ITW_HOME=%~dp0/../
-set INST_JAVA_HOME=
+set BAD_SLASH_SCRIPT_DIR=%~dp0
+set SCRIPT_DIR=%BAD_SLASH_SCRIPT_DIR:\=/%
+set ITW_HOME=%SCRIPT_DIR%../
+
+rem the following is for testing-only and not intended to be robust
+rem will not work from 32-bit firefox
+for /f "tokens=*" %%a in ('%windir%\System32\reg query "HKLM\SOFTWARE\JavaSoft\Java Development Kit"') do set "version_key=%%a"
+set "version=%version_key:~58%"
+for /f "tokens=*" %%a in ('%windir%\System32\reg query "HKLM\SOFTWARE\JavaSoft\Java Development Kit\%version%" /v JavaHome') do set "jh_key=%%a"
+set BAD_SLASH_JAVA_HOME=%jh_key:~22%
+set REG_JAVA_HOME=%BAD_SLASH_JAVA_HOME:\=/%
+"%REG_JAVA_HOME%/bin/java.exe" -version
+if errorlevel 0 if not errorlevel 1 (
+    set JAVA_HOME=%REG_JAVA_HOME%
+)
 
 if "%JAVA_HOME%" == ""  (
   if not "%INST_JAVA_HOME%" == ""  (