Difference between revisions of "Tutorials:Calculating Hash Sum"

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*1. Re-download. Delete the '''ISO''' and download again. Probably the easiest option that will work for everyone, only problem is on a slow connection could take forever (again). <i>NOTE: If after downloading the '''ISO''' several times from same location and the '''ISO''' still doesn't match, please report the Mirror on the [http://www.ultimatebootcd.com/forums/ Forums] and try another location.</i>
 
*1. Re-download. Delete the '''ISO''' and download again. Probably the easiest option that will work for everyone, only problem is on a slow connection could take forever (again). <i>NOTE: If after downloading the '''ISO''' several times from same location and the '''ISO''' still doesn't match, please report the Mirror on the [http://www.ultimatebootcd.com/forums/ Forums] and try another location.</i>
  
*2. Torrent. If you can, fastest way to get the correct copy, but more complicated, is to open the torrent file in your favorite Bittorent program and start the download. Then <u>stop</u> the download, and copy the mismatched ISO to the download/temp location and force the program to re-check the file. If it worked right, then the program will automatically download missing pieces needed to complete the '''ISO'''.<br/><br/>
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*2. Torrent. If you can, fastest way to get the correct copy, but more complicated, is to open the torrent file in your favorite Bittorent program and start the download. Then <u>stop</u> the download, and copy the mismatched '''ISO''' to the download/temp location and force the program to re-check the file. If it worked right, then the program will automatically download missing pieces needed to complete the '''ISO'''.<br/><br/>
 
[[Image:uTorrent-Picture1.jpg|400px|center|frameless]]
 
[[Image:uTorrent-Picture1.jpg|400px|center|frameless]]
 
<center>Shown is uTorrent (freeware) and right clicking on the torrent to "Force Re-Check".</center>
 
<center>Shown is uTorrent (freeware) and right clicking on the torrent to "Force Re-Check".</center>

Revision as of 03:34, 18 February 2011


Introduction

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 other Tutorial regarding the ISO. Compare with Download Page MD5 Sum. If you would like to more information regarding Checksums/Hashsums please see the Wikipedia article.


NOTE: If you can download through the torrent instead of HTTP/FTP, it can prevent you from having to check the ISO Checksum/Hashsum as it auto-checks the ISO; therefore you can safely disregard this article.


Windows

  • 1. Freeware programs: Hashcalc (Requires installation) or Checksum (No installation required). More options from this Softpedia list (Some freeware, may require installation).
  • 2. After installation, drag ISO onto program (or desktop shortcut) and it will auto generate the MD5 Sum.

Linux

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:
HASH_SUM_HERE UBCD###.iso

# = version number

Checksum Doesn't Match?

Your options are:

  • 1. Re-download. Delete the ISO and download again. Probably the easiest option that will work for everyone, only problem is on a slow connection could take forever (again). NOTE: If after downloading the ISO several times from same location and the ISO still doesn't match, please report the Mirror on the Forums and try another location.
  • 2. Torrent. If you can, fastest way to get the correct copy, but more complicated, is to open the torrent file in your favorite Bittorent program and start the download. Then stop the download, and copy the mismatched ISO to the download/temp location and force the program to re-check the file. If it worked right, then the program will automatically download missing pieces needed to complete the ISO.

UTorrent-Picture1.jpg
Shown is uTorrent (freeware) and right clicking on the torrent to "Force Re-Check".