Identifying drupal installation on windows I don't want a google custom search to be shown on my development system which is on windows but it should be visible when on production system which is on Linux.

How do I check it?

This isn't working out. I've placed this code in the block "Pages on which this PHP code returns TRUE (experts only) " but it does not work in my Windows installation:

&lt;?php
if(  file_exists("C:"))
{
return false;
}
return true
?&gt;
You can achieve this by implementing the php_uname() function:

$os_name = php_uname("s");
if($os_name == 'Linux') {
  return TRUE;
}
//can apply additional checks for other OS
else {
  return FALSE;
}