my files got zipped and cant be unzipped
 

hi just a quick question I am running vista and nortons 2007 and yesterday i downloaded some songs and they were playing fine then today i got up and they had all been zipped and when i tried to unzip them it says "file is corrupt from transfer" and wont unzip. and the few that weren't zipped say" limewire will not launch the specified file for security reasons" please help