Download
FAQ
Errors can occur during the download, even if your download
manager reports none. Therefore it is very
important to check that the files have not been
corrupted in any way. This is the purpose of the
SHA1SUM file. It contains one line for each
of the available ISO files with a content verification code called
a hash computed from the original ISO files.
![[Note]](./stylesheet-images/note.png) | BitTorrent Automatic Error Checking |
|---|---|
BitTorrent automatically performs this error checking during downloads. If your BitTorrent application reports all files have been successfully downloaded, you can safely skip this step. |
There are a number of free (as in cost) products available for file validation and hashing that have point and click interfaces. Here are links to a few of them:
HashCalc: http://www.slavasoft.com/hashcalc/
eXpress CheckSum Calculator (XCSC): http://www.irnis.net/soft/xcsc/
Follow the instructions provided to install the program. When you run the program, use the file selection tools provided to select your downloaded ISO image files. Then select the SHA-1 algorithm for calculation, and run the tool. The program takes some time to complete, since it must read the entire ISO file.
Open the file SHA1SUM with a text editor,
such as WordPad, to display its
contents. Make sure the hash displayed by the hash tool for
each of the downloaded ISO
files exactly matches the
corresponding hash in the SHA1SUM file.
If all of the hashes match, you can then burn the ISO files to media. If a file does not match, you may have to download it again.
![[Important]](./stylesheet-images/important.png) | CAVEAT EMPTOR |
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The Fedora Project and Red Hat Inc.. have no control over external sites such as the ones listed above, or the programs they provide. |
To check the files using the command prompt, you need to
download the program sha1sum.exe. For
instructions and the link to download the program, refer to
http://lists.gnupg.org/pipermail/gnupg-announce/2004q4/000184.html.
The sha1sum.exe program computes and
displays hashes. To use it, save
sha1sum.exe to the same directory as the
ISO files. Select Run... from the Start
menu and then enter cmd for the name of
the program to start a Command Prompt
window. Then change into the download directory. Run
sha1sum with each ISO file like this:
cd "C:\Documents and Settings\Owner\My Documents\My Downloads\Fedora" sha1sum.exe F7-Prime-i386-disc1.iso
The program takes some time to complete, since it must read the entire ISO file.
Open the file SHA1SUM with a text editor,
such as WordPad, to display its
contents. Make sure the hash displayed by
sha1sum.exe for each of the downloaded ISO files
exactly matches the
corresponding hash in the SHA1SUM file.
If all of the hashes match, the ISO files can be burned to media. If a file does not match, you may have to download it again.