I have a dvd I want to boot from, on a certain laptop.

The problem is this:
DVD will NOT boot in laptop [1] with this DVD.
DVD WILL boot ok in laptop [2] with this DVD.
- Conclusion, DVD is ok.

* laptop [1] and laptop [2] boots other media in the cd/dvd drive ok.

I can see all files on DVD in both laptops.

As a workaround I copied the DVD image off the DVD drive to internal hard disk with following command and the result was as follows:

- result of dd command
# dd if=/dev/sr0 of=/dev/sda4
6298816+0 records in
6298816+0 records out
3224993792 bytes (3.2 GB) copied, 473.18 s, 6.8 MB/s


How do I make that partition [/dev/sda4] bootable ?
Thanks Glenn

FIRST check your BIOS/CMNOS settings for boot order (see below)
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or... Try a partition manager such as:
Linux: Parted, Gparted
Windoz: Paragon partition manager, EASEUS partition master
See wikipedia: -search for disk partitioning
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Then mark your partition (/dev/sda4) ACTIVE. This makes it bootable, AND also renders other partitions NOT BOOTABLE.
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Better to check your BIOS settings (CMOS menu, accessible when you first boot, usually by press/holding F1 or Del or Esc or F10) and make sure that your DVD drive appears BEFORE your hard disk on the boot order menu. That way you don't risk messing up your hard disk's bootability !
-Best of luck from kendeacon

I'd reburn the dvd using a good quality dvd or maybe a few brands but burn it at the very slowest burn speed. Your assumption is not exactly correct. You can only assume that the dvd does work on a computer, you haven't proven anything yet.

Second could be to verify that any dvd can be used to boot the computer? Can any burned dvd and can any commercial dvd such as windows 7 or vista?

As to how to boot an image we might be able to use grub to load it. One problem is you can't exactly dd a dvd to a partition that I have even heard of but might be wrong on that. Might be easier to simply use it as an iso image or transfer the files and then boot it with grub4dos or grub. I think the better way would be to install it in a VM or other real partition and then dd that vm or real filesystem to a partition.