Why won't my Vista machine accept 3.6.10?
I have no problem downloading the browser, but when I try to run the download I get the message that (a) the file does not have a valid digital signature that verifes its publisher, and (b) if you try to run it anyway, it says the file is corrupt.
ప్రత్యుత్తరాలన్నీ (1)
It is possible that your anti-virus software is corrupting the downloaded files or otherwise interfering with downloading files by Firefox.
You can try to disable the real-time (live) scanning of files in your anti-virus software temporarily to see if that makes downloading work.
See http://kb.mozillazine.org/Unable_to_save_or_download_files