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Why does my PC restart itself when trying to boot off of a Linux Ubuntu CD?

I’m running Windows 7 Home Premium 64 bit. It’s Linux Ubuntu 11.10 64-bit that
I’m trying to install; burn the CD with Image Burn. If I set to boot priority
CD, I get a ‘prefix missing’ error. If I finally boot, I get the purple splash
screen, it will restart. What am I doing wrong?

Ubuntu’s a great operating sytem that I use here at home on a couple of
machines – a laptop on which I watch videos while exercising and on a desktop
that actually runs as my local DNS and database server.

In this video excerpt from a recent Ask Leo! webinar,
I’ll discuss a couple of things to try to help diagnose the problem and point
to a useful resource when dealing with Ubuntu related issues.


View in HD (1280×720)

Update: The “MD5 hashes” that I couldn’t locate in the video can be found here: Ubuntu MD5 Hash page.


Why does my PC restart itself when trying to boot off of a Linux Ubuntu CD? Running Windows 7 Home Premium 64-bit. It’s Linux Ubuntu 11.10 64 bit that I’m trying to install; burn the CD with Image Burn. If I set to boot priority CD, I get a ‘prefix missing’ error. If I finally boot, I get the purple splash screen, it will restart. What am I doing wrong?

So, I’m not sure what you mean by ‘boot priority CD’ or, I’m sorry, I’m not sure by what you mean by ‘prefix missing’ as compared to manually booting. Somehow, you’re apparently able to boot off the CD, so I’m not quite sure what’s happening there.

So, Ubuntu Linux supports a large number of machines – many, many machines. I’ve actually been fairly impressed with it’s version of plug and play where it just runs pretty much anything that you can throw at it. However, that’s not to say that it runs everything.

It’s very possible that the machine that you are attempting to install on simply isn’t supported. Now, what I will suggest you do, just as a test, is to grab the 32-bit version of Ubuntu and see if that will boot and possibly install, although I’ll leave the install decision up to you.

If it does, then obviously that points to something about the 64-bit version not necessarily working or being compatible with your machine. The other thing that comes to mind is after you’ve downloaded the image of the CD before you burn it, check the MD5 checksum. If you take a look at the Downloads for Ubuntu… I’m not necessarily going to take the time to look for it now, but what they typically include with a number of downloads is what’s called an MD5 checksum and what that is is it’s a number that is calculated mathematically by, for lack of a better term, let’s just say they’re adding up the values of all the bytes in your disc image. [Update: They can be found here.]

It’s actually more complicated than just adding them up, but you get the idea. What that allows you to do then is to download this image, recalculate the MD5 checksum, and there are definitely tools available for Windows that will let you calculate the MD5 checksum and then compare the result that you get with the result that is published on the website.

That will tell you if the download was successful and nothing was damaged in the image as compared with what they provided you. It’s a long shot. I’ve really seen an image not get downloaded properly because there’s so much error checking going on in the download protocol, but it is something at least worth looking into if you continue to have this kind of problem. But like I said, the very first thing to test would be the 32-bit version and take it from there.

The other thing I was going to mention, also is that I certainly have run Ubuntu. I have a couple of machines here running it constantly but it’s not my deepest area of expertise. One of the places I would point you to is There, you’ll get basically peer-to-peer support, support from other, more knowledgeable Ubuntu users. Many of whom are more than happy to try and help you with the specifics of whatever kind of a problem you might have.

That’s actually, these days, a pretty general rule of thumb; for almost any software, you might find is that most manufacturers, most organizations that produce software have put together user support forums. Not only because it’s cheaper for them, it’s not support that they then have to provide, but it’s also a great opportunity for you and me to go in and talk to people who have potentially a lot more experience with a specific piece of software – in this particular case, Ubuntu.

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1 thought on “Why does my PC restart itself when trying to boot off of a Linux Ubuntu CD?”

  1. By all means try the tried and true versions first. This means 10.04 or 10.10. The later version are very problematic with the unity desktop.

    I prefer SuperOS that is Ubuntu with all the codecs built right in.

    A simple google search will bring you to the proper website. You will have to hunt around but you will find the older versions. These always work and will do anything you want them to do.

    USBcreator will install it to a USB drive that you can boot off of.


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