Ask Ubuntu is a question and answer site for Ubuntu users and developers. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I set up dual boot on my extra pc last night.

First installed windows 7 and that went just fine.

Downloaded Ubuntu and then did the MD5SUM and did not get a correct return that were listed on the site.

I forgot to do that before I burnt the image to a disc, so I booted from the disc anyway to do the intergrity check and no errors were found.

I then installed and everything seems fine except when it's booting, the purple screen is broken. should I try to redownload and re install?

share|improve this question

When you see the Grub menu, hit the e key.

This special mode of Grub allows you to temporarily modify Ubuntu's boot parameters.

Add to the end of the line:


If this worked, do the following once Ubuntu is loaded to make the change permanent:

gksu nano /etc/default/grub

Change the line that looks like:


So that it now reads:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi=off"

Save the file, then run:

sudo update-grub
share|improve this answer

The difference in the md5sum that you see is telling you that you have a download that was corrupted in some way. There's a difference in the iso file that may, and probably has, caused you problems.

The Integrity check only tests to see if the disk is 100% readable, it does not mean that the iso was not corrupted during download.

You will need to get the iso again. If you have a problem downloading reliably then you should use one of the torrent downloads since torrents have built-in block testing and recovery in case of corruption. I've had one or two corrupted iso files from normal downloads over the years, but not one since I started using torrents for downloading them.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.