couldn't able to solve the problem!!

[ramakrishna pydipati]

I had java in my system it used to work properly,
but when I reformatted the system, I tried to load java again ,then I couldn't able to load it properly I am getting these errors!!
my java is in
JAVA_HOME:C:\Sun\AppServer\jdk;
CLASSPATH:C:\Sun\AppServer\jdk\bin;
Path:C:\Sun\AppServer\jdk\bin;
on command prompt:
if give command >java it's working properly;
but when I give "javac" I am getting the following errors
>javac
Error opening registry key 'Software\JavaSoft\Java Runtime Environment'
Error: could not find java.dll
Error: could not find Java 2 Runtime Environment.

[Igor Ko]

It's installation problem,
It seems that you tried to restore files, likes java.exe...
But you have to reinstall java system in Windows
(to set also Windows registry, dll... and other things)

[ramakrishna pydipati]

Thank you ,u r right
now I deleted every thing and started now I am getting a new error
i.e,
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld
Press any key to continue . . .

I checked my path&classpath and JAVA_HOME everything is semms to be ok
can u help me out
Thanks in advance

[Layne Lund]

Will you post the command that causes this error?

[Srivani Nallan]

Check the main function. You might have spelled it wrong in the method.

[Dirk Schreckmann]

I am getting a new error
i.e,
Exception in thread "main" java.lang.NoClassDefFoundError: HelloWorld
Press any key to continue . . .
I checked my path&classpath and JAVA_HOME everything is semms to be ok
An improperly configured CLASSPATH will cause this problem. What is your CLASSPATH setting? Does it include the current working directory specified with a period?
Are you 100% certain that the HelloWorld.class file was generated during compilation?

[roy joseph]

forgetting to include "." in your classpath can cause head-aches. one way to see if java installed properly is to run a class and explicitly stating its class path.
ex.
your class is here:
c:\java\hello.class
so run it like this:
java -cp c:\java\ hello
even if you are inside the directory where your class is present, without explicitly specifying the classpath you would get an error.
ex.
if you havent change your classpath to include the ".". doing this wont work.
c:\java\java hello