This document is provided "as is" without warranty. Use at your own
risk. In no event shall I be liable for any damage resulting from the
use of this work.
This HOWTO applies if:
- Your machine already has Windows installed, and you are
installing Linux as a second operating system, and
want to leave the Windows boot loader (NTLDR) on the MBR (Master Boot
Record). This allows you to continue to boot Windows with no issues.
I've heard that Windows 2000/Windows XP or anti-virus software may
complain if the MBR does not contain the Windows boot loader
can use either GRUB or LILO to dual-boot Windows 2000/Windows XP and
Linux. Both functionally work fine, but from what I've read, GRUB
requires less maintenance, as LILO requires you to reinstall the boot
loader (by running /sbin/lilo) every
time you rebuild the kernel or make changes to /etc/lilo.conf.
for /boot Partition
The location of the /boot partition
on the hard drive is critical so that you don't get screwed by the
infamous BIOS 1024 cylinder limit.
The BIOS of older systems can't access data beyond cylinder 1024, which
is ~8.5 GB. A simple way to avoid the BIOS 1024 limit is to create /boot within
the first 1024 cylinders (~8.5 GB) of the hard drive. If
you have multiple hard drives (disks), /boot must be
on the same hard drive (probably the first hard drive) that has the
Windows boot loader (NTLDR) on the MBR.
Here are some options for
where to create /boot partition.
I did) Shrink the Windows partition such that there is 50 MB of unused
disk space at the beginning of the drive and lots of space after the
Windows partition. You can install the /boot Linux
partition in this first 50 MB and avoid any potential issues with the
1024-cylinder limit entirely.
- Shrink the Windows partition such that it does not cross
the 1024 cylinder (~8.5 GB), and install the /boot partition
right after the Windows partition.
- Use LBA (Logical
Block Addressing). LBA allows you to boot beyond the 1024 cylinder. In
order to use LBA, your BIOS must support it. In addition, for LILO, you
must also add a flag to enable LBA support. GRUB supports LBA "out-of-the-box"
To non-destructively shrink
the Windows partition, you can use the free software programfips (please
note that fips does not currently support NTFS partitions). Another
option is the excellent commercial product Partition
It has an easy-to-use GUI. Unfortunately, the tool that comes with Red
Hat 7.2, Disk Druid, does not have the ability to shrink existing
partitions. Once you've shrunk the Windows partition, you can use Disk
Druid during the Red Hat Installation to create all the partitions you
need for Linux.
Following are the steps to
get dual-boot working with GRUB; I figured out how to do this by
looking at a similar procedure for
LILO. I've verified that this works for Windows 2000 and Windows XP,
and this should work on Windows NT (all 3 OSs use the same booting
- Install GRUB on the first sector of the /boot partition. DO
NOT INSTALL IT ON THE MBR!.
If you are performing the Red Hat installation, for the
"Boot Loader Installation" screen:
- Select "Use GRUB as the boot loader"
- Select Install Boot Loader record on "...First sector
of boot partition".
- After finishing the Red Hat installation, reboot into
Linux. If you don't have a boot disk, try booting in linux rescue mode
If you already have Linux installed:
- Determine which partition contains the /boot partition
by running the df command.
You'll see output like this:
Filesystem 1k-blocks Used Available Use% Mounted on
From this output, we see that /boot is on /dev/hda2.
/dev/hda3 8665372 1639580 6585612 20% /
/dev/hda2 46636 5959 38269 14% /boot
/dev/hda6 513776 189504 324272 37% /osshare
none 256624 0 256624 0% /dev/shm
- Make a copy of the Linux boot sector onto a floppy or onto
a FAT32 partition. We'll name this copylinux.bin.
To make a copy onto a floppy:
To make a copy onto a FAT32 (vfat) partition:
- Mount the FAT32 partition if it's not mounted yet. If
it isn't listed in the df output,
it hasn't been mounted yet. Check out steps
3a-3c for mounting a FAT32 partition on the
"Share Partitions HOWTO".
- Run the following command: dd if=/dev/hda2
of=/osshare/linux.bin bs=512 count=1
Substitute the path for the if= parameter
(the input file) with the appropriate partition from the previous step.
E.g., set if= to /dev/hda2.
Substitute the path for the of= parameter
(the output file) with whatever is appropriate for your system. The
example here (of=/osshare/linux.bin)
is for copying onto a FAT32 partition called osshare.
- Reboot into Windows
- Copy the linux.bin file to C:\
- Run notepad and edit C:\boot.ini. Note
that C:\boot.ini is a
hidden system file, so it probably won't show up in Windows Explorer.
To edit the file, try: Start->Run and
enter: notepad C:\boot.ini.
Add the following line at the end: c:\linux.bin="Linux"
If your C: filesystem
is NTFS (not FAT32), you must edit C:\boot.ini as a
user with administrator-level privileges.
For reference, here is a copy of my boot.ini file.
To make C:\boot.ini
you can either :
- Use Explorer:
- Go to Tools->Folder
select Show hidden files and folders and
deselect Hide protected operating
system files (Recommended).
- Right-click on the file, view the Properties and
uncheck Read-only. You
can now edit the file.
- After editing the file, restore the settings to
their original state.
- Use the command-line:
- Make the file writable: attrib -R -S -H C:\boot.ini.
- After you've finished editing the file, put the
settings back: attrib +R +S +H C:\boot.ini
- Reboot again. You should be able to pick either Windows or
Linux. Selecting Linux will start GRUB
- When I select Linux from the boot
menu, I get a frozen "GRUB" (or an "L" in the case of LILO)
sure you created the linux.bin file
correctly with the dd command.
If you think you ran the command correctly, the problem may be that your /boot partition
is beyond cylinder 1024 and your BIOS can't reach it. At system
startup, the Windows boot loader lists the choices from boot.ini. When
you select Linux, the boot loader then loads the 512-byte linux.bin file,
and then BIOS tries to access the /boot partition
to run GRUB. Some BIOS implementations can only address the first 1024
cylinders of a hard drive, which corresponds to ~8.5 GB. How do you fix
your /boot partition
before cylinder 1024; i.e. before ~8.5 GB.
I select Linux from the boot menu, I get an error message that says
"Windows XP could not load: The file hal.dll (windows/system32/) is
missing or corrupt. Please reinstall.
is usually caused by an error in the boot.ini file.
If you are unable to find and fix the error, check out Kelly Theriot's page that
provides various methods for addressing the problem.
- Jimmy Andriambao: for recommending the link regarding
- Leif Roger Kolberg: for creating a Norwegian translation of this page
- Dirk Goepfert: for creating a German translation of this page
- Fred van Lieshout: for creating a Dutch translation of this page
- Rostislav "Udo" Galicek: for creating a Czech translation of this page
- Arun Swami: for validating the dual-boot setup with
multiple hard drives. Thanks Arun!
- Adrián I. Correa: for enthusiastically providing a Spanish
translation of this page. Adrián said it best: "I love this
wonder called The Internet!"
- Devesh Mistry: for pointing out the use of chroot /mnt/sys/mnt/syimage when in
linux rescue mode
- Emmanuel Brun: for graciously providing a French
translation of this page
- Jason Noll: for reporting the hal.dll problem resulting
from error(s) in boot.ini
- Garth Patil: for helping to troubleshoot why GRUB was
freezing and having a great sense of humor
- Piete Brooks: for pointing out that editing C:\boot.ini requires
administrator-level privileges and providing the content for making the
file editable using Explorer
- Paul Feehan: for providing the commands to make C:\boot.ini editable
for Windows XP
- Jan Holm Jensen: for reporting that C:\boot.ini is a
hidden system file
- Hampus Hedberg Hankell: for the following suggestion:
think you should add help for users in despair that already have
installed grub on mbr ,thus loosing the their ability to boot into
windows xp. Procedure for this is ,boot from a windows start disc and
do a fdisk /mbr At least then they can reach their windows and this
time doing it right
- Mark Jordan: for verifying that this works on Windows XP
and suggesting the content for copy to floppy
- Darryl Eaton: for
introducting me to Red Hat Linux
hope you found the content on this page useful (and accurate). Please email me with
feedback and corrections.
If you are interested in
creating a translation of this page, please read the translation
Raiders run the 3-4 defense and Coryell offense and had
a good 2005 draft.
Copyright © 2005 Ed