hello Techy375,

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 scan of files in your anti-virus software to see if that makes downloading work.

Tried disabling the anvtivirus and firewall, and still same issue.

Try the full setup instead as some antivirus may have a issue with the stub installers. http://www.mozilla.org/en-US/firefox/all/

The link can be found on mozilla.org under the green download button.