since this morning when i click on firefox to open it a box comes up and says that firefox has crashed. So i tied to download firefox again from www.firefox.com website but it still doesn't download it

since this morning when i click on firefox to open it a box comes up saying that firefox has crashed. so i tried to re-download firefox from www.firefox.com website but it doesn't download it and i don't know what to do can someone help please? thank you. == User Agent == Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729; WinTSI 16.01.2010)