It is possible that your anti-virus software is corrupting the downloaded files or otherwise interfering with downloading files by Firefox.
Try to disable the real-time (live) scanning of files in your anti-virus software temporarily to see if that makes downloading work.

See "Disable virus scanning in Firefox preferences - Windows"

• http://kb.mozillazine.org/Unable_to_save_or_download_files

Does not help to disable virus protection.\ I can download the Firefox application but when I go to install it get error message corrupted file I suspect the profile is corrupted Where is the profile stored for windows 7? Thanks

Problem now is I cannot get firefox to install I unistalled the other version and when I go to install it nothing happens I downloaded software ok to my computer When I click run nothing happens