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I have been trying to get Ubuntu 12.04.1 (desktop-i386) running on my laptop. Have burned a boot-able CD containing 12.04.1. It allows me the option of Trying out Ubuntu before installing, but the installation fails. It cites an input/output error Errno5.

I have tried burning another disc and using another USB disc drive, but they all give the same result as above.

I then downloaded the alternate-i386 and loaded it onto a boot-able USB flash-drive. During installation, it produced an error as well, and selecting the option to check the CD's integrity produced the following:

The ./pool/main/1/linux/nic-usb-modules-3.2.0-29-generic-pae-di_3.2.0-29.46_i386.udeb file failed the MD5 checksum verification. 
Your CD-ROM or this file may have been corrupted.

Proceed to check the integrity of the aforementioned CD produced the same message as well. Any help guys? Really want to get Ubuntu up and running.

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possible duplicate of "errno 5 - input/output error" when trying to install – Eric Carvalho Aug 19 '15 at 13:10

You should check the hash sums of the downloaded ISOs. You can get the hash sums (md5sum or sha1sum) from

To check the md5sum:

  • Go the directory where you downloaded the ISO.

  • Compute the md5sum:

     md5sum ubuntu-12.04.1-desktop-i386.iso 
  • Check if the sum is same as the one given on the link above. In this case the correct md5sum should be e235b63c02644e219b7bf3668f479c9e.
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Besides checking the md5sum, try to avoid the fancy programs on the ISOs as those caused errors for me on 12.04.1 and try a simple dd. Assuming your USB stick is /dev/sdb, do a:

sudo dd if=<path to iso> of=/dev/sdb
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