WinZip (A Useful tool): While working on the computer system, in almost every type of set up, you surely would find the need to use WinZip software some or the other time to compress large sized files. This helps in speedy transfer of data via emails and other modes like online chat. You can also transfer huge & bulky files/folders quickly from one system to another using USB or other storage drives with the help of this compression facility, which saves your time greatly. The process of zipping and unzipping the files/folders is very quick and highly secure. Moreover, this also saves your download time and even helps in encrypting and decrypting documents containing sensitive information.

Zip Files: The compressed files, formed using WinZip software, generally have .ZIP extension. These Zip files mainly use MIME (Multipurpose Internet Mail Extensions) media type application or Zip.

Corruption (Errors Observed in Zip Files): Due to some internet problems, you can observe certain errors in your Zip files, which generally occur while downloading these Zip files, leads to their corruption. As a result, the data stored in these Zip files can become inaccessible to you.

A Possible Scenario: Imagine a situation, where you tried to open a .Zip file after downloading it from a MS Windows SharePoint Services document library and you get an error message stating: "Cannot open file: it does not appear to be a valid archive. If you downloaded this file, try downloading the file again." You Zip file data become inaccessible after this error message appears.

Possible Cause: The abovementioned situation may occur when the HTTP compression is turned on in the Microsoft Internet Information Services (IIS) Web Sites properties on the SharePoint virtual server. Consequently, when you download the Zip file, IIS encodes it as GZIP and the browser client forwards it directly to the unZip program, without GZIP decoding the file.

Restore from Backup (A Solution to the Problem): If you are experiencing such problem of data inaccessibility due to corrupted Zip files, then there is a way you can get back your data and i.e. by restoring the data from a recent backup file. However, if you had forgotten to create or never maintained a backup or your backup also has got corrupted, then in that problematic scenario, you can get a third-party (http://www.ziprepairtool.com) Zip File Repair Tool to repair damage Zip file.

Zip Repair Tool: You can repair Zip files using an outside Zip Repair Tool. SysTools Zip Repair software is an efficient tool that you can easily use to fix Zip file error. The software incorporates very powerful scanning algorithms to fix Zip files and to ensure complete recovery of your Zip file data. SysTools Zip Repair software is specially designed to Repair Damage Zip Files in almost all the corruption issues. Using this tool is highly safe as it maintains your data integrity owing to its non-destructive nature. The software is very easy to use and screen instructions are very easy to comprehend. This useful application is compatible with almost all Windows versions including Vista, XP, 2003, and Windows 7.