Don't you just hate it when you try to open a ZIP archive and it won't open because it's corrupted. Zip archives can become corrupt for numerous reasons: maybe you have it on a old floppy disk or CD with read errors, or a download did not complete.
There are many tools available which promise to recover the data from such broken archives.
Most of these applications come with a price tag. We came across a free (for personal use) tool called DataNumen Zip Repair that promises to repair zip archives.
When you run the program, you're met with a welcome screen which has options to subscribe to a newsletter, buy a business license and enter the license key. You can ignore all of those and click on "Continue Personal, non-commercial use."
A buy banner and social link are displayed in the interface but they don't distract too much from the actual options.
The interface lists four tabs at the tap, the first being repair. You can use the "Select Zip" option to browse your computer to select a broken archive. The second field, "Repair and extract the items to directory", defines where the content of the zip archive is extracted to (if possible).
The entire process requires just two steps: pick a zip file and select a destination directory for its files. Once done, hit the start repair button to start the recovery process. The program displays the progress in the interface under repair process log.
Note: Zip repair programs cannot magically
The Batch repair works similarly, but lets you choose multiple archives to recover data from. In addition to this, there is a search tool which can be used to search your computer for Zip archives.
My question about the program was, does this really work? Well, there's only one way to find out. You can perform these tests yourselves if you want to.
Since I didn't have a corrupted ZIP archive handy (I usually delete them), I decided to create one. The oldest trick in the book is just to create a new archive and open it in notepad to add something to it. The ZIP file is ruined.
7zip and Windows Explorer's archiver wouldn't open the file. Unfortunately DataNumen Zip Repair wasn't able to recover it either.
We download files all the time, sometimes the download may get interrupted, and we end up with a corrupted file. So all I had to do was download a zip and disable the internet midway through. I downloaded a copy of my Wallpaper's collection from my Dropbox, and switched off the Wi-Fi before it could finish downloading. This is definitely a corrupted archive. The only extra step I had to do was to rename the incomplete download from .part to .ZIP. The testing process was the same and Windows Explorer wouldn't open it.
7zip did but said that the archive had errors. I extracted the contents to a folder anyway. Time for DataNumen Zip Repair to prove its worth. And it said that it recovered the data.
Now obviously it couldn't have the complete archive because I hadn't finished downloading it, but according to the program it did manage to salvage the contents of the corrupted archive.
Imagine if this was actually a priceless archive with photos from the past, or some important documents or something. That would be really amazing.
Anyway, back to our tests. What did it recover? That's what matters. I compared what 7zip extracted with what DataNumen had done. The former had 9.19MB worth of files (7 files in 5 folders) vs 37.5MB for the latter (32 files in 9 folders). Looks like we have a winner. I didn't want to believe this and re-tested it again.
The 7Zip folder only had 5 usable photos, the other folders were empty. I'm assuming the program skipped the rest of the archive because it had errors. Shockingly, the contents of the folder extracted by DataNumen Zip repair were all usable. I wasn't expecting this at all, I expected the same 5 files that the 7zip folder had and the rest to be corrupted. I opened every single picture in Windows Photo Viewer expecting to be greeted by an error. But it actually worked.
Maybe I'm nitpicking here, but I wish there was a portable version of the application. This is clearly not a software you'd be running everyday. Not bad for the price of free, right?Advertisement
Ghacks is a technology news blog that was founded in 2005 by Martin Brinkmann. It has since then become one of the most popular tech news sites on the Internet with five authors and regular contributions from freelance writers.