javac is not recognized as an internal or external command, operable program or batch file
Usage: javac <options> <source files>
Where possible options include:
-g Generate all bugging info
-g:none Generate no bugging info
-g:{lines, vars, source} Generate only some bugging info
Etc....
1. The javac command returns error since the javac executable path is not recognized by the OS. Correct your java home path to C:\Program Files\Java\jdk1.6.0_21 (remove the \bin)
2. The java command returns a different version because it refers to the java installed which comes along with the OS. I hope you have given your custom path installation as the First variable as you mentioned in the Path. But it might look into C:\Program Files\Java\jdk1.6.0_21\bin\bin based on the java home you have configured.
javac is not recognized as an internal or external command, operable program or batch file
Usage: java [-options] class [args...]
(to execute a class)
or java [-options] -jar jarfile [args...]
(to execute a jar file)
where options include:
-client to select the "client" VM
-server to select the "server" VM
-hotspot is a synonym for the "client" VM [deprecated]
The default VM is client.
-cp <class search path of directories and zip/jar files>
-classpath <class search path of directories and zip/jar files>
A ; separated list of directories, JAR archives,
and ZIP archives to search for class files.
-D<name>=<value>
set a system property
-verbose[:class|gc|jni]
enable verbose output
-version print product version and exit
-version:<value>
require the specified version to run
-showversion print product version and continue
-jre-restrict-search | -jre-no-restrict-search
include/exclude user private JREs in the version search
-? -help print this help message
-X print help on non-standard options
-ea[:<packagename>...|:<classname>]
-enableassertions[:<packagename>...|:<classname>]
enable assertions
-da[:<packagename>...|:<classname>]
-disableassertions[:<packagename>...|:<classname>]
disable assertions
-esa | -enablesystemassertions
enable system assertions
-dsa | -disablesystemassertions
disable system assertions
-agentlib:<libname>[=<options>]
load native agent library <libname>, e.g. -agentlib:hprof
see also, -agentlib:jdwp=help and -agentlib:hprof=help
-agentpath:<pathname>[=<options>]
load native agent library by full pathname
-javaagent:<jarpath>[=<options>]
load Java programming language agent, see java.lang.instrument
-splash:<imagepath>
show splash screen with specified image