title: This is how I installed JRuby on Windows -> Why did it not work?
body: <pre><code>* Download JRuby 1.20. (zip file)
  * Extract the zip into C:\JRuby120
  * Edit sytem "environment variables":
  * Add JRUBY_HOME -&gt; point it to C:\JRuby120
  * Modify the PATH environment variable to point to C:\JRuby120\bin; 
  </code></pre>
  
  <p>After all this, I open up cmd.exe and type <strong>jruby</strong></p>
  
  <p>->"The system cannot find the path specified"</p>
  
  <p>What did I do wrong?</p>
  
  <p>I removed echo_off from C:\JRuby120\bin\jruby.bat, C:\JRuby120\bin_jrubyvars.bat and C:\JRuby120\bin_jrubyvmopts.bat and invoked jruby from cmd.exe. This was the output:</p>
  
  <pre><code>C:\&gt;rem --------------------------------------------------------------------------- 
  
  C:\&gt;rem jruby.bat - Start Script for the JRuby Interpreter 
  
  C:\&gt;rem
  
  C:\&gt;rem for info on environment variables, see internal batch script _jrubyvars.bat 
  
  C:\&gt;setlocal
  
  C:\&gt;rem Sometimes, when jruby.bat is being invoked from another BAT file, 
  
  C:\&gt;rem C:\JRuby120\bin\ is incorrect and points to the current dir, not to JRuby's bin dir, 
  
  C:\&gt;rem so we look on the PATH in such cases. 
  
  C:\&gt;IF EXIST "C:\JRuby120\bin\_jrubyvars.bat" (set FULL_PATH=C:\JRuby120\bin\ )  ELSE (set FULL_PATH=C:\JRuby120\bin\ ) 
  
  C:\&gt;call "C:\JRuby120\bin\_jrubyvars.bat"  
  
  C:\&gt;rem Environment Variable Prequisites: 
  
  C:\&gt;rem
  
  C:\&gt;rem   JRUBY_OPTS    (Optional) Default JRuby command line args. 
  
  C:\&gt;rem
  
  C:\&gt;rem   JAVA_HOME     Must point at your Java Development Kit installation. 
  
  C:\&gt;rem
  
  C:\&gt;rem ----- Save Environment Variables That May Change -------------------------- 
  
  C:\&gt;set _CLASSPATH=.; 
  
  C:\&gt;set _CP= 
  
  C:\&gt;set _JRUBY_CP= 
  
  C:\&gt;set JRUBY_BAT_ERROR=0 
  
  C:\&gt;rem ----- Verify and Set Required Environment Variables ----------------------- 
  
  C:\&gt;if not "C:\Program Files\Java\jdk1.6.0_11\bin" == "" goto gotJava 
  
  C:\&gt;set JRUBY_HOME=C:\JRuby120\bin\.. 
  
  C:\&gt;rem ----- Prepare Appropriate Java Execution Commands ------------------------- 
  
  C:\&gt;if not "" == "" goto gotCommand 
  
  C:\&gt;set _JAVA_COMMAND= 
  
  C:\&gt;set JAVA_COMMAND=java 
  
  C:\&gt;if not "Windows_NT" == "Windows_NT" goto noTitle 
  
  C:\&gt;rem set _STARTJAVA=start "JRuby" "C:\Program Files\Java\jdk1.6.0_11\bin\bin\java" 
  
  C:\&gt;set _STARTJAVA=C:\Program Files\Java\jdk1.6.0_11\bin\bin\java 
  
  C:\&gt;goto gotTitle 
  
  C:\&gt;rem ----- Set up the VM options 
  
  C:\&gt;call "C:\JRuby120\bin\_jrubyvmopts"  
  
  C:\&gt;set _MEM=-Xmx500m 
  
  C:\&gt;if not defined JAVA_MEM goto memOptDone 
  
  C:\&gt;set _STK=-Xss1024k 
  
  C:\&gt;if not defined JAVA_STACK goto stackOptDone 
  
  C:\&gt;set _VM_OPTS= 
  
  C:\&gt;set _RUBY_OPTS= 
  
  C:\&gt;set _DFLT_VM_OPTS= 
  
  C:\&gt;set _JAVA_VM=-client 
  
  C:\&gt;set SAFE_JAVA_HOME=C:\Program Files\Java\jdk1.6.0_11\bin 
  
  C:\&gt;set SAFE_JAVA_HOME=C:\Program Files\Java\jdk1.6.0_11\bin 
  
  C:\&gt;rem
  
  C:\&gt;rem Can you believe I'm rewriting batch arg processing in batch files because batch 
  
  C:\&gt;rem file arg processing sucks so bad? Can you believe this is even possible? 
  
  C:\&gt;rem http://support.microsoft.com/kb/71247 
  
  C:\&gt;rem Escape any quotes. Use _S for ', _D for ", and _U to escape _ itself. 
  
  C:\&gt;rem We have to escape _ itself, otherwise file names with _S and _D 
  
  C:\&gt;rem will be converted to to wrong ones, when we un-escape. See JRUBY-2821. 
  
  C:\&gt;set _ARGS= 
  
  C:\&gt;if not defined _ARGS goto vmoptsDone 
  
  C:\&gt;set _VM_OPTS= -client -Xmx500m -Xss1024k  
  
  C:\&gt;set _DFLT_VM_OPTS= 
  
  C:\&gt;set _MEM= 
  
  C:\&gt;set _STK= 
  
  C:\&gt;set _ARGS= 
  
  C:\&gt;set _VAL= 
  
  C:\&gt;set _CMP= 
  
  C:\&gt;set _CMP1= 
  
  C:\&gt;set _JAVA_VM= 
  
  C:\&gt;set _RUNJAVA="C:\Program Files\Java\jdk1.6.0_11\bin\bin\java" 
  
  C:\&gt;rem ----- Set Up The Boot Classpath ---------------------------------------- 
  
  C:\&gt;for %i in ("C:\JRuby120\bin\..\lib\jruby*.jar") do @call :setjrubycp %i 
  
  C:\&gt;if not "" == "" goto addjrubycp 
  
  C:\&gt;set JRUBY_CP=C:\JRuby120\bin\..\lib\jruby.jar 
  
  C:\&gt;goto :EOF 
  
  C:\&gt;for %i in ("C:\JRuby120\bin\..\lib\bsf*.jar") do @call :setjrubycp %i 
  
  C:\&gt;if not "C:\JRuby120\bin\..\lib\jruby.jar" == "" goto addjrubycp 
  
  C:\&gt;set JRUBY_CP=C:\JRuby120\bin\..\lib\jruby.jar;C:\JRuby120\bin\..\lib\bsf.jar 
  
  C:\&gt;goto :EOF 
  
  C:\&gt;rem ----- Set Up The System Classpath ---------------------------------------- 
  
  C:\&gt;for %i in ("C:\JRuby120\bin\..\lib\*.jar") do @call :setcp %i 
  
  C:\&gt;if not "" == "" goto add 
  
  C:\&gt;set CP=C:\JRuby120\bin\..\lib\bsf.jar 
  
  C:\&gt;goto :EOF 
  
  C:\&gt;if not "C:\JRuby120\bin\..\lib\bsf.jar" == "" goto add 
  
  C:\&gt;set CP=C:\JRuby120\bin\..\lib\bsf.jar;C:\JRuby120\bin\..\lib\jruby.jar 
  
  C:\&gt;goto :EOF 
  
  C:\&gt;if not "C:\JRuby120\bin\..\lib\bsf.jar;C:\JRuby120\bin\..\lib\jruby.jar" == "" goto add 
  
  C:\&gt;set CP=C:\JRuby120\bin\..\lib\bsf.jar;C:\JRuby120\bin\..\lib\jruby.jar;C:\JRuby120\bin\..\lib\profile.jar 
  
  C:\&gt;goto :EOF 
  
  C:\&gt;goto :EOF 
  
  C:\&gt;if 0 == 0 "C:\Program Files\Java\jdk1.6.0_11\bin\bin\java"  -client -Xmx500m -Xss1024k  -Xbootclasspath/a:"C:\JRuby120\bin\..\lib\jruby.jar;C:\JRuby120\bin\..\lib\bsf.jar" -classpath "C:\JRuby120\bin\..\lib\bsf.jar;C:\JRuby120\bin\..\lib\jruby.jar;C:\JRuby120\bin\..\lib\profile.jar;.;" -Djruby.home="C:\JRuby120\bin\.." -Djruby.lib="C:\JRuby120\bin\..\lib" -Djruby.shell="cmd.exe" -Djruby.script=jruby.bat org.jruby.Main   
  
  C:\&gt;set E=3 
  
  C:\&gt;call "C:\JRuby120\bin\_jrubycleanup" 
  </code></pre>