Hi,
I have got a new PC with Win 8.1 64 bit. Installaed avast free (currently 2015.10.0.2208). In most (if not all) cases I now try to download something from Internet (using Firefox), the download does not seem to be complete (if it is an exe, the exe cannot be run; if it is a zip, the zip cannot be opened). After switching avast off, it works. For example:
I have just downloaded a zip of about 23Mb, three times with avast switched on, once with avast disabled. All four files have different sizes, differing by between 40 and 1000 kB; and all three downloaded with avast on are corrupted.
Thanks for any help.