ISO issues



Hi there,

Could anyone please help me in understanding what an ISO image is? I am asking this question for I have recently downloaded the Avira Rescue System 2014 and in the description I read that an ISO image is to be automatically burned on a CD or in a USB Stick by the application: " Die im Download enthaltene Anwendung brennt selbständig ein ISO-Image auf USB-Stick oder einen CD- oder DVD-Rohling. Von diesem Medium müssen Sie Ihren PC dann starten."

BTW I have also downloaded the Rufus 1.4.12, which also deals with ISO images and boot from USB, but I still cannot fully realize what all this means. The OS boots from the USB? And what next, if it is so? It goes on running from the USB (or the CD) for the rest of the session? What is the main purpose of all this?

May sound utterly newbyish all this, but nevertheless I had to ask somewhere, for I’m burning in curiosity about this…


There are a couple of manuals here:
I’m going to recomend the you write(burn) the .iso to a CD -R with ImgBurn .
I havn’t ever burned this program but I’m fairly certain that will work.

Then you boot your computer with this CD.
There are instructions in the manual but basically you need your CD drive to be the first in the boot order in your Bios.
From there you will be able to use the various functions of this CD to try & repair your OS.

After you gain some experience with the CD if you still think you need a bootable USB drive the manuals have some instructions for doing that as well.


It sounds like the download should be able to automatically create a bootable CD or USB (without needing Rufus)

To use one, the system must support booting from the device, and be set to do so in preference to the hard disk (BIOS boot order).

Yes, it boots and runs from the CD or USB (or quite often, creates a RAMdisk to run from).

The purpose, is to be able to carry out recovery operations when the hard disk has problems, and without anything on the hard disk being active and possibly interfering).

Similarly, a bootable antivirus CD is often the best way to dislodge a virus with too much self-defence to shift once active.


Thanks for the info, I somehow missed the fact that the BIOS boot order has to be reconfigured indeed, but now a new question arises in me (due to my still overwhelming lack of experience): how does one reconfigure the boot order in order to be able to use a bootable CD or stick if the system cannot be started? Or is it that if I push the start button on the laptop, then a menu appears that allows me to reconfigure the boot order before the OS starts running? I have already watched a couple of tutorials about this by Carey Holzman, but the starting process is still somehow confusing for me, for my understanding is that the first thing which activates after switching on a PC is the OS, but now I guess I am being quite wrong on this assumption…

I’d be grateful indeed for a clarification on this…


Well It’s not that I am completely clueless about informatics… have had my laptop for over 2 and a half years, and till now I was able to sort out any kind of problem, including virus issues… but I have still never encountered a problem which would have forced me to boot from “outside”, so to say, that is why this is still a fairly unexplored land for me.


Usually the “start up” screen will have some “F key” options .
Select the one that seems correct. The likely ones are F1 or F2 .


Yes, there is often a flash of “press SOMETHING” for setup… the key used varies between makers, but F1, F2 or DEL seem to be the most common … or is that “missing keyboard, press F1 to continue”


All clear, thanks!