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MD5sum ISO File Check

MD5 stands for Message-Digest algorithm 5. MD5 hashes (text strings) are used to check if a file downloaded correctly or if correct file was downloaded.

An MD5 hash (or checksum) is a 32 character hexadecimal number that results from running md5sum program in order to check a downloaded ISO file. Any difference between two hashes (text strings) such as the one downloaded with ISO file and MD5 file signifies that either an error occurred during download of ISO file or the wrong ISO file was downloaded or the wrong MD5 file was downloaded.

An MD5 hash file is nothing more than a text file ending in .md5 which contains a text string. The MD5 hash has the same name as downloaded ISO file, but ends with an .md5 or .txt extension. Example: puppy-release.iso.md5.txt

HashTab For All Versions of Windows

Download and install HashTab. In Windows Explorer browse to ISO file, right click file and select Properties. Click File Hashes tab. After MD5 hash of ISO is displayed click Compare a file button, then browse to md5.txt for ISO file and select it. Integrity of ISO file is tested and either verified or denied. If ISO file passes integrity check a green check mark icon will appear next to Compare a file field.

MD5sums For All Versions of Windows

If you're using DOS or DOS-based versions of Windows (Windows 95, 98 & ME included) you can use this MS-DOS compatible freeware application: md5sum.exe. Right click on file name and choose Save Link Target As then save it in same directory as your downloaded ISO file.

How To Check MD5 In Puppy Linux (all versions):

  1. Go to Menu > Filesystem > ROX-Filer File Manager
  2. Browse to directory where you downloaded Puppy Linux ISO file.
  3. Open a console there: Right click window then select Terminal here.
  4. Type md5sum followed by exact name of ISO file you downloaded. Example: iso_file_name.iso
  5. Press Enter.

Shown below is an example a message you should see containing MD5 hash. The hash must exactly match hash of MD5 file you downloaded from same source as ISO file:

# md5sum pup-430-small.iso
5971d2ace9760931de7b9f4b34ffd3ca  pup-430-small.iso

Now compare this text string with the text string shown in the MD5sum hash file you download and confirm that they are the same. These two text strings should match exactly. If they do not match exactly then ISO file is corrupted or is an incorrect file.

Note: An MD5 check is not necessary with BitTorrent download as it will automatically check and correct any errors.

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