Corrupt Download?

CORRUPT ZIP FILE RESOURCE PAGE

It seems after lots of feedback that the problems seem to lie in that browsers are wrongly identifying certain files when the website compresses them on the fly. It basically works like this, web site sends the compressed zip file but as it sends it, the file is again compressed on the fly to speed up transfer. The browser is supposed to identify that this is happening and so when it gets the file it unpacks the file and saves the original zip file. The problem arises when the browser just saves the recompressed file as a zip without first unpacking it back. You then try to unzip a zip file that isn't really a zip file and so get the corruption error.

The best solution is to use either a good browser and the one of choice is firefox or a download manager or even both.

I have at the end of the page listed the links for Firefox for both PC & MAC and also a good download manager again for both.

Should you not want to change or are already using Firefox or a download manager then carry on reading.

INTERNET EXPLORER PROBLEMS

First thing to note is that windows Internet Explorer does not always correctly identify the correct mime type and can download a server compressed zip file, saving it as .zip without un-gzipping first leaving the resulting file showing as corrupt.

If you have a problem using IE then you can try renaming any file downloaded from .zip to .gzip and see if it will extract leaving the original .zip file for you to unpack by your usual method.

You could also try changing your internet options -> advanced -> and un-tick Use HTTP 1.1 then click Apply and OK.

This sometimes helps rectify the problem.

ie advanced options

So now that bit is out of the way lets tackle another problem. Do you use windows compressed folders to extract your files? If you do then the next bit may be of interest as there is a recognised problem that is known to Microsoft, there is a fix but again this does not always have a 100% success rate and no other fix has come forward to my knowledge.

anyway heres the details of the problems:

When you download a Zip (.zip) file in Microsoft Internet Explorer, you may experience either of the following behaviors:
The file appears to download, but the file compression program that you use (for example, WinZip) opens and displays a blank window.

When you search for the file, you are unable to locate it. The file does not exist on your hard disk.

-or-

If you are running Microsoft Windows XP, and you use the Compressed (zipped) Folders feature as your file compression program, you receive the following error message:
The Compressed (zipped) Folder is invalid or corrupted.

the fix for it can be found by clicking HERE (will open in a new window)

STILL THINK YOU HAVE A CORRUPT FILE ? DON'T RE-DOWNLOAD YET!!!

You may find that you have still done things from the above and that the file is still not working.

The thing is the file may still not actually be corrupt and using a proper archive utility will be able to extract it.

If you are on a windows machine then I recommend any of the following 3 as they are all free and all work well.

One of them even has an added advantage as it includes a zip repair utility !!

There are loads of free archivers out there so the choice is yours.

YOU DO NOT HAVE TO PURCHASE WINZIP OR WINRAR TO EXTRACT ARCHIVES!!

Izarc (windows) the utility with built in zip repair tool - information here download here

7zip (windows) is a widely recognised archiver/ dearchiver that is held with high regard - information and download here.

Jzip (windows) is another nice piece of software - information here download here.

Sorry if you are on a Mac as there isn't agreat deal of free stuff about but you can try Stuffit Expander. information and download here

If you already have a 3rd party de-archiver installed and it won't work you could try the following windows utility. It will attempt to repair the zip file and is usually successful.

Once again this utility is free so well worth a try. Information here download here.

SO YOU ARE NOW SURE THE FILE IS CORRUPT

READ BEFORE RE-DOWNLOADING ELSE YOU WILL WASTE YOUR TIME!!!

If you get a corrupted zip file the most likely cause is packet loss during the download process.

This means that even the slightest glitch in the internet between our servers and your computer can cause even a few packets to be lost. Zip files must be downloaded with 100% accuracy to insure that you get the entire, complete and correct file. *Even if one packet is lost during the download process the zip file will not open.*

So, if something happens during the first download attempt, can’t you just try to download the file again? The answer is no, probably not.This is because your browser will dutifully cache all files, even zip files.

Your browser doesn’t know that something went wrong on the first download attempt, so if you try to download the zip file again, your browser will check its local cache first. If it finds the zip file there, then it will appear to be downloading the file again, but really what you are getting is the file that it already downloaded, which of course is corrupted. You can repeat this as many times as you like, but as long as your browser has a corrupted version of the zip file in it’s cache, you always get the same corrupted copy of the file until you clear the cache.

*The thing to do then is clear your browser cache before downloading the zip file again.*

How do I clear my web browser's cache and cookies?

Each time you access a file through your web browser, the browser caches (stores) it. In this way, the files (including any images on the page) do not have to be retrieved anew from the remote web site each time you click the Back or Forward buttons. You should periodically clear the cache to allow your browser to function more efficiently.

If you do not see instructions for your specific version or browser, search your browser's Help menu for "clear cache".

If you are unsure of exactly what browser version you are using, from the Help menu, select About [browser name].

Internet Explorer 8

From the Safety menu in the upper right, click Delete Browsing History... .
Check Temporary Internet files, Cookies, and History, and then click Delete.

Internet Explorer 7

From the Tools menu in the upper right, select Delete Browsing History.
Next to "Temporary Internet Files", click Delete files... .
To delete your cookies, click Delete Cookies.
Click Close, and then click OK to exit.

Firefox 3.5 for Windows

From the Tools menu, select Clear Recent History...
From the Time range to clear: drop-down menu, select the desired range; to clear your entire cache, select Everything.
Click the down arrow next to "Details" to choose what history elements to clear (e.g., check Cookies to clear cookies).
Click Clear Now.