Can´t reactivate ASA

Hi all, i purchased ASA about 2 months ago, and i had no problem at all using it, i activated it and it was all great. But, 3 days ago, i open it with no internet connection (i didn´t check the connection before open ASA) so it couldn´t connect properly to servers, then a message came up: "your key is not valid or it hasn´t been activated, click here to automatically activate your key". I clicked and it said that the key was wrong, and then i had the option to manually enter the key. I did it and it accepted it, but then, about 3 secs later, the "your key is not valid...." message came up again, then i did the same steps, and the message came up again and again, over and over. (all of this with my internet connection already working fine). I have no firewall nor anything that can be blocking ASA connection to servers, in fact i haven´t changed anything since i purchased ASA, and it was running fine until 3 days ago. Well, i uninstalled ASA and reinstalled it; big mistake i guess, because now i can´t even initialize the program because it tries to automatically activate the key, then it says the key is wrong, and that´s all, i can´t manually enter the key like i did before, so at the moment i can´t even open ASA =(.
PS: i bought and downloaded ASA installer flie in another pc (a laptop) than in which i installed it and have been running it. i don´t know if that has something to do.
Any help?
Thanks!