hello everyone, thanks for your replies...
well, i havent tried to copy those files into another disk, i run them directly from my usb hdd because on win7 computer i just have the common compatibility problems, i'll try to cpty them to local hdd, and yes i can write my data into usb hdd, some weeks ago i had problems because win7 removed all permission from my disk (i dont know if it happened at college or at home, im admin in my both) home computers and when i realized about that i went to my hoime's computer and restored the permissions, i don't know if there are limitations on usb drives, thanks for your help i'll try your suggestions...