Hi Liu,

It sounds like your downloading problem might have to do with the transfer of data from A-->B as opposed to the goodness of the actual file on the server. Zip files tend to get corrupt depending on your internet connection (a direct connection is always better than wireless), the size of the download (bigger = longer download = more opportunity for corruption), the browser that you are using (IE is evil), or some combination of those things. Generally, the solution is to keep trying until you get lucky (for example, with a subset of the ADHD 200 it took me 5-6 tries to get one of the zipped up data sets in a not-corrupt state). Internet Explorer (at least the last time that I used it) has a gzip encoding option that can also lead one astray... I would proceed as follows:

1) Find the best internet connection that you can
2) Try downloading again
3) If you are unable to change the gzip encoding option in IE explorer, just try other browsers
4) As a sanity check, see if anyone else can download and unzip the file.  If they sit next to you, get a USB stick :o)
5) If you want to use IE, see this --> http://kb.winzip.com/kb/entry/150/
6) It probably wouldn't make a difference, but JZip is a nice alternative to WinZip, which isn't free forever
6) Keep trying :o)  If someone else can do it, that means it will eventually work for you too!

And here is some general background information about zip files: http://kb.winzip.com/kb/entry/35/

Good luck!

Best,

Vanessa