I found the answer in this site: "http://www.adobe.com/devnet/air/article ... _apps.html"
Thanks to David Deraedt for writing this article. It was really helpful for someone who doesn't know about AIR.
Here's the answer I found (only part of the article):
On the importance of the application ID
As you probably know, AIR applications are identified by the runtime and the OS through an application ID, a string that you provide in your application descriptor XML file. This ID serves several purposes:
It ties the application to the so-called Application Storage Directory.
It is also used to tie the application to its Encrypted Local Store.
It is used by the runtime during the update process to determine what application is to be replaced.
These are only some of the reasons why you should never change an application ID after you've published a build, unless you want it to be treated as a completely new application. Note that, in some rare cases, this may actually be what you want, in order to let users install and use each of these versions independently.
In most cases, though, you must choose your application ID before the first public release, and never change it. Using a reverse DNS naming scheme such as "com.mycompany.myapplication" used to be considered good practice in early beta versions of Adobe AIR. However, it is no longer necessary since the application ID now combines with the publisher ID to identify the application.
You don't have to worry if you have to change the commercial name of your software after a public release (for legal issues, or because the marketing said so, for example); the application ID is not related at all to the name under which the application will appear on the system while running, or during the install process—users of your application will never have to see this ID.
Note that the application ID is not the unique criteria for identifying an application. For security reasons, two applications with the same ID but built with different signatures will also be considered as different applications, unless a proper migration procedure has been put in place.
Ok, I hope I was able to help. Pass it on ...
