Question

I am confused here:
If I run java from cmd then the command runs succesfully.
But I have neither set JAVA_HOME nor %JRE_HOME% nor added java/jre installation directory in my PATH.
So when I do

echo %JAVA_HOME%

No JAVA_HOME is displayed (expected since I have not set it)

If I do:

echo %JRE_HOME%`

No JRE_HOME is displayed (expected since I have not set it)

and when I do

echo %PATH%

no directory in the PATH points to a java installation. Expected since I have not modified PATH to add java.

PATH is:

C:\Program Files\Common Files\Microsoft Shared\Windows Live;  
C:\Program Files (x86)\Common Files\Microsoft Shared\Windows Live;  
C:\Program Files (x86)\AMD APP\bin\x86_64;  
C:\Program Files (x86)\AMD APP\bin\x86;
C:\Windows\system32;C:\Windows;  
C:\Windows\System32\Wbem;  
C:\Windows\System32\WindowsPowerShell\v1.0\;  
C:\Program Files (x86)\ATI Technologies\ATI.ACE\Core-Static;  
C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\;   
C:\Program Files\Microsoft SQL Server\100\Tools\Binn\;  
C:\Program Files\Microsoft SQL Server\100\DTS\Binn\;  
C:\Program Files (x86)\IDM Computer Solutions\UltraEdit-32;  
C:\Program Files (x86)\Windows Live\Shared  

So why don’t I get Bad Command on running java?

Answer 1

According to this answer to “Is there an equivalent of ‘which’ on windows?”, recent versions of Windows include a ‘where’ command.

So you could try: where java.exe

I can’t check right now, but I have a feeling Windows had a java.exe somewhere under C:\Windows\System32\…