How to easily check file hashes

You install many programs, therefore you download a lot of files off the net. From time to time, when you try to run them, you get a "file corrupted"-type of error and you have to download again. Sometimes it's worse: no error, but the program you install keeps malfunctioning and you just can't figure out why... Can't think of anything even worse? How about files downloaded from alternative links hosted on servers broken into or controlled by hackers? You could be installing something "extra" along with that program and have no idea whatsoever.

The solution is to make use of file hashes. Hashing is a method of associating (almost uniquely) a file with a string of characters. Given the hash of the original file, you can check your downloaded copy is not corrupted by comparing its hash with the original.

UNIX-like systems users have several command line-based tools for computing file hashes (eg: md5sum), but there aren't any built into MS Windows. Fortunately, there is a small gem that takes care of this inconvenience. Word from the developer:

"HashTab is a Windows shell extension which adds a tab called "File Hashes"
to the Windows Explorer file properties. The tab contains the MD5, SHA1 and
CRC-32 file hashes. These are common hashes that are used to verify the
integrity and authenticity of files. Many download sites list the MD5 hash
along with the download link. The HashTab makes it very simple for Windows
users to check these hashes on any file on the system without using external
tools."

To view a file's hashes, just right click on it and choose "Properties".

To compare the resulting hashes with one you obtained from, say, the website that provided the file, just paste the hash in the corresponding field and click on "Compare". Clicking on the "Compare" button without pasting a hash first enables you to choose a second file and use its hash instead.

Check out the images nearby for a feel about how this works.

HashTab is completely free to use and does not contain any adware or spyware. In fact, its complete source code is available upon request, from the product's homepage




*** RELEVANT LINKS ***

Official HashTab Homepage

Download HashTab 1.11 32bit (installer, 188KB, md5=65F36ABE5EBAFF6803A84E3AF76350C7)

Download HashTab 1.11 64bit (installer, 184KB, md5=53EB1568E694030F1414F8F310155FA6)