Tutorials:Calculating Hash Sum

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Revision as of 23:08, 19 February 2011 by StopSpazzing (talk | contribs) (Checksum/Hashsum Doesn't Match?)


This guide will help to confirm you have exact copies of UBCD ISO to prevent any problems later down the road. This should be your FIRST step before continuing with any of the other Tutorials regarding the ISO. If you would like more information regarding Checksums/Hashsums please see the Wikipedia article.

DISCLAIMER: The only trusted MD5/SHA1 Sums are located on the downloads page.


  • 2. After installation (or extraction for portable), drag ISO onto program (or desktop shortcut) and it will auto generate the MD5 Sum. Compare with download page MD5/SHA1 Sum.


Ubuntu and similar flavors:

  • 1. First open a terminal and goto the directory you downloaded the ISO into:
cd download_directory

  • 2. Then run the following command from within the download directory.
md5sum UBCD###.iso

  • 3. md5sum should then print out a single line after calculating the hash:

# = version number

Checksum/Hashsum Doesn't Match?

Your options are:

  • 1. Re-download. Delete the ISO and download again, this time try choosing another mirror. Probably the easiest option that will work for everyone, only problem is on a slow connection could take forever (again).

  • 2. Torrent. By only downloading the missing pieces to complete the ISO, could save you valuable time and thus be faster than re-downloading the whole ISO again. This is more complicated than just downloading a file, therefore, only proceed if you are experienced with torrenting:

DISCLAIMER: The only trusted torrent files are located on the downloads page.

  • 2a. Open the torrent file, located on the downloads page, in your favorite Bittorent program and start the download.
  • 2b. Then stop the download, and copy the mismatched ISO to the download/temp location, overwriting the torrent download ISO.
  • 2c. Followed by forcing the program to re-check the file. (See picture)

Shown is uTorrent (freeware) and right clicking on the torrent to "Force Re-Check".

  • 2d. If the ISO is anything less than 100%, you will have to press the "play" or "start" button to continue downloading the rest of the ISO.
  • 2e. After the file reaches 100%, check the MD5/SHA1 checksum codes of the ISO image using the instructions above to confirm.

Note: There are many different Bittorent programs, please see documentation for your program if you are having issues.