Question: I created a setup by Advanced Installer software for my program that I've written by c#. I installed my program on VMWare Windows7.

When I try to run it this message is displayed:

![Class not registered](https://i.stack.imgur.com/efAyh.png)

Answer: 
May be this link will help to get proper understanding.

```
http://stackoverflow.com/questions/5478996/should-java-string-method-local-variables-be-initialized-to-null-or

```
Because the designer of Java language believes it made more sense for it to be! Codes are easier to read when variables are initialised. A statement `String foo;` feels non-deterministic because you have to guess what's the default value of String is whereas `String foo = null;` is more deterministic.

To give you a more obvious example, consider this:

```
int x;
Int y;

```

Can you very quickly guess what the default values are? You probably have to pause for a few second to realize x is probably 0 and y is probably null