On 12/8/06, BombayNews bombaynews@hotmail.com wrote:
Boot from CD: Disk Boot Failure. Insert System Disk and Press Enter
If the system was boot up from Harddisk( you mentioned Boot from CD??) and you got this error that means MBR in your harddisk is corrupt be it GRUB or XP.
I thought GRUB was independent of XP and corruption in XP files would not matter.
Yes. GRUB is independent of XP. It works like this. The system is capable to read only the first sector of any bootable device. (Harddisk or CDROM or any other bootable device). This sector should contain the Master Boot Record(MBR). No MBR then "Non-System Disk". MBR has the information which partition contains Operating Systems. The first sector of any partition is called the Boot Sector. In windows only environment MBR points to the first sector of the partition where window$ is installed (c drive). This boot sector contains information to load the boot.ini file which contains the location of OS boot files of any window$ OS. This line in your file is [multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /noexecute=optin].
The case is different when GRUB is installed. It is installed on the MBR (also can be installed on the boot sector of any partition) and it has the ability to read and load the first sector of any partition. When you select XP in the grub boot menu it actually reads the refered boot sector and the boot sector has the code to load the boot.ini file. Note that XP has nothing to do with this behaviour of grub. XP comes into picture only after you select XP in grub boot menu. So if XP files are corrupted GRUB should still work fine provided you have not tried to fix XP by doing something with command "fixmbr" in Windows. If you run this command then window$ will overwrite the MBR in turn removing grub from MBR and makes your Linux unbootable. window$ cannot and does not want to detect your Ubuntu. Shame on them.
But the engineer says XP is the primary system installed on the machine with Linux running on other partitions so corrupted XP would mean that the machine would not start at all.
Thats not right if grub was the bootloader. Otherwise it should be that window$ boot Linux and got itself corrupted. Are you sure your engineer did not do anything other than restoring XP boot files? Can you still boot to Ubuntu? Is grub still your boot loader?
If I am getting carried away or if there is a simple explanation for this someone in the list please correct me. :-)