No way to make capcha work on localhost

[eluser]RiccardoC[/eluser]
I was working with captcha, but there's no way to obtain the array I need in local (on the web it work)
Here is my code

Code:

$vals = array(
  'img_path' => 'C:/mywebzone/captcha/',
  'img_url' => base_url() . 'captcha/',
);  
$captcha = create_captcha( $vals );

I also used

Code:

'img_path' => 'C:\\mywebzone\\captcha\\'

and

Code:

'img_path' => './captcha/';

Whatever I try, the $captcha variable contain an empty string (not an array as expected)
The strange things is that if I put the code on the server, it work perfectly and the $captcha variable contain the expected array

Any idea?

[eluser]RiccardoC[/eluser]
another information
I tried this

Code:

$handle = fopen("c:\\mywebzone\\captcha\\prova.txt", "w");
fclose($handle);
$handle = fopen("./captcha/xxx.txt", "w");
fwrite( $handle , "Prova testo" );
fclose($handle);

And it worked perfectly, thus it looks like it is not a folder auth problem

[eluser]RiccardoC[/eluser]
Solved! The GD extension wasn't loaded in my PHP
This is the solution (for other dumb like me people )

open your php.in file (usually c:\php folder)
look for this line

Code:

;extension=php_gd2.dll

Remove the semicolon and it will look like this

Code:

extension=php_gd2.dll

Restart your apache server and all will work properly!