I was very happy today to discover that one of our suppliers had high-resolution product images available for download. Since taking good product pictures is not done in a snap, this had the potential to save me lots of time. Unfortunately, after downloading the 30MB ZIP I received the following error message when trying to open it: “The Compressed (zipped) Folder is invalid or corrupted”. Downloading the file again didn’t make a difference. Sure, I could’ve asked the supplier to provide me with an uncorrupted file, but I knew this would take a while.
That’s why I went looking for software which might be able to fix the ZIP file. I quickly found two affordable programs: Zip Repair Pro and Advanced Zip Repair. Unfortunately, the trial version of Zip Repair Pro only repairs files up to 5 MB. Not wanting to spend 29,95 US$ to find out whether or not the ZIP file could be repaired, I gave Advance Zip Repair a try. This software uses a different approach: It will try to repair the file and show a report, but it won’t output the fixed file unless you register (29,95 US$). Repairing the ZIP file I had downloaded was no problem for Advance Zip Repair. However, seeing the report it became clear to me that the file didn’t contain the images I needed anyhow. 🙄
Click thumbnail to see the repair report: 
Nevertheless, since only the last file was not completely recoverable I became curious and gave WinZip 10.0 and 7zip a try, too. Both programs are “regular” un-zip applications and not meant to be used for repairing ZIP files. Indeed, both were unable to open the archive (“Cannot open file: It does not appear to be a valid archive”).
Now please excuse me while I uninstall everything again…