With AIR 1.5.2 your only option is to use Merapi, a socket server, or a web service running on the local machine. It would be difficult but not impossible. If you can wait until AIR 2.0 you'll have the ability to cross that system boundary directly.
Actually my motive for getting the system id is to give my Air App some protection from being copied. Basically i want that if someone install my Air app then the user is not able to use that app to some other system. We are providing the serial key with the software and an online activation also.But that person can use the same software with key and give to others also or we can say do piracy.
So i was thinking that once he install the software on his system then he must have to activate the software using the serial key and at the same time the system id(hardware id) will also be saved on our database, so if that person install the software on the same system again then the software checks the hardware id from our database and give the permission to use the software. And if he try to install the software on any other system, he will not be able to install it.
But i dont think this is possible or totally secured.
If you can tell me some other way to secure my app then do write me.