README: How to burn and boot a linux install cd/dvd
Almost daily I help someone who has not been able to boot their linux cd/dvd.
I will try and cover the following:
burning as an image
setting up the BIOS for booting
OK, when you download an .iso image from a mirror there is a chance it could have been corrupted in the download, since .iso images can be large files up to 700+Mb for cds and 4.7Gb for dvds. You can check if the download has been corrupted or not with md5sum. This is a checksum algorithm which gives a number/letter output for files such as the .iso file.
How is this useful? Well if you have this you can compare it to the md5sum of the download.
Usually on the mirror you downloaded from there will be a file with either a list of all the md5sums for the .iso files in that directory. Or there will be a md5sum file for each .iso file, usually named filename.iso.md5. If there is no md5sum file there grab one from the distro's main server.
Now that you have the original md5sum for the downloaded .iso file you must compare it with the md5sum of the download. To do do this in linux use the md5sum command: this will spit out a number/letter mix. Compare this with the original md5sum from where you downloaded. If they match you are fine and go on to the next section. If they do not match you need to try downloading the file again.
If you are in windows you should run the downloaded .iso through a program like fsum and see if the output matches. If the output matches go on to the next step, if it doesn't, try downloading again.
Burning the .iso file as an image to a cd/dvd
Do not simply copy the .iso file to the disk. That is one of the main errors people who are not used to burning .iso images make. You must burn an .iso file to the cd/dvd as an image for it to work properly. Most burning software has an option to "Burn as an image", or something similar, and that's the option you want to use. I have never had problems doing this under Linux using the K3B burning application. You can search Google for "free CD burning applications" to find lots of software options, or see the link at the bottom of this post for some options. You can also use software such as Nero or Roxio to do this, but I have heard about people having problems with Nero, and I myself have had problems with Roxio when burning an .iso image. Be sure you do not take steps to make the new disk bootable, and do not extract the .iso file before burning it because the .iso image burning process takes care of those steps automatically.
To get the best results burn the cd/dvd at the lowest speed possible, I tend to burn cds at x4 speed. I do this because it lessens the chance that the burn will go badly and give out a dud cd at the end. I have never had any coaster (dud cd) come out of burning at these low speeds.
You might find this a bit annoying since it is of course slower than burning at higher speeds, but by doing it at a slower speed it can save you having to burn more than one of the same disk.
Setting up BIOS for booting a cd/dvd
Ok by now you should have a bootable cd or dvd. You should now enter your computer BIOS, and make sure that the dvd or cd drive is before the hard drive in the list of boot devices.
You can usually enter your BIOS at bootup by pressing one of these keys:
If you are unsure, or can't find the correct key it should be mentioned in the user manual that came with your motherboard, or PC.
Once in the BIOS make sure that the cd or dvd drive is before the hard drive, then put the cd/dvd in the drive, save the config in the BIOS and then exit the BIOS.
Your computer should now restart and boot the cd or dvd.
* Moderator Edit (ozar): For specific instructions on properly burning ISO images to disk using some of the various burning applications that are available, take a look here:
How to successfully burn or write an ISO-image to cd or dvd