User`s guide

You may have noticed that you get good IE downloads of .zip files from some
sites-- WinZip unzips the files with no problem. But, from other sites, the .zip
files cannot easily be unzipped or, sometimes, not at all.
One idea I've come across is that, starting with IE 6, Microsoft began to
require that download sites provide information about .zip files, perhaps other
kinds of files, too. If the information is supplied, the file arrives okay. If
not, you get a 'bad' .zip file.
Either way, there is nothing wrong with the .zip file maintained on the
site. The problem is with how IE treats .zip files.
What's happening is that the bad zip files have been gzipped and that is
how they arrive, still with the ".zip" suffix. The good zip files are either not
gzipped or, if they were, are sucessfully un-gzipped upon arrival.
WinZip, at least the versions I've tried, is confused by a gzipped file
with a ".zip" suffix and will not unzip it. A solution that usually works is to
rename the file, say "Narf.zip", to "Narf.gz". WinZip will ungzip the file and
ask you to supply a suffix, which should be ".zip". Now, you have a .zip file
which WinZip can unzip.
The above seems to work in most cases; but, not always. I've come across
one case where either the initial file could not be unzipped or ungzipped or the
resulting .zip file could not be unzipped. Via an ftp connection to the site, I
downloaded the file; it unzipped with no problem.
Evidently, the gzipping may introduce an error, at least as far as WinZip
and 7-zip are concerned.
A simple solution is to use some browser other than IE when planning on
downloading .zip files. For instance, on my Windows ME computer, .zip file
downloads from Apple II sites under Netscape 4.78 work fine. Firefox users
report the same result.