I already try to delete firefox from program files,then delete from recycle bin,then instal the new one,still doesn't work. Then i try to uninstal firefox, instal the new one,still doesn't work. When i click the firefox shortcut nothing happened, it says nothing.. I try to click ctrl+alt+del to show the task manager,but there's no firefox there, it doesn't running.. the firefox didn't exist or what?? Is it crashed? but there's no notice says that my firefox is crashed.. Or is it corrupted?? I really don't know what to do, since i'm a beginner.... Please help me to find the solutions...i really need to work on something..and i need my firefox to back in bussines... What should i do?? is there a problem with the program or..i don't know..i'm using windows vista by the way.. Thank you very much for the help...