4.4. Dual Booting Linux and Windows NT/2000
As we said earlier, when you run Windows NT, its boot loader
expects to be the one in charge; therefore, the
normal way to dual boot Windows NT
and Linux is to add Linux as an option on the NT boot menu. The information
in this section also applies to Windows 2000, which uses the NT loader.
To accomplish this, you need to provide the NT loader with a copy of the
Linux boot sector. Here's how you do that on a computer running
Windows NT with an NTFS filesystem (note that Windows NT should
be installed on your system already). See the NT OS Loader+Linux mini-HOWTO
for more information and other alternatives.
You should have a Linux boot
floppy available so that, if necessary, you can boot Linux before the
NT boot loader has been modified. You also should have
a DOS-formatted floppy to transfer the boot sector to the Windows NT
partition. If LILO is already installed, you may need to modify
/etc/lilo.conf as described later. Otherwise,
you'll either install
LILO as part of the Linux installation, or you can install it with
the QuickInst script that comes with LILO. Once LILO
and you have a configuration file, you can set up the system for dual booting.
Note that the following instructions assume your Linux partition is on
/dev/hda2. If Linux is on another partition, be
sure to replace /dev/hda2 in the
following examples with the correct partition.
Specify the Linux root partition as your boot device. If you are
editing /etc/lilo.conf manually, your entry will look like this:
and will be the same as the root= entry.
Run the lilo command to install LILO on the Linux root partition.
At this point, if you need to reboot Linux, you'll have to use the boot
floppy, because the NT loader hasn't been set up yet to boot Linux.
From Linux, run the dd command to make a copy of the Linux boot sector:
% dd if=/dev/hda2 of=/bootsect.lnx bs=512 count=1
This command copies one block, with a blocksize of 512 bytes, from the
input file /dev/hda2 to the output file /bootsect.lnx. (The
output filename can be whatever makes sense to you; it doesn't have to
Copy bootsect.lnx to a DOS-formatted floppy disk:
% mount -t msdos /dev/fd0 /mnt
% cp /bootsect.lnx /mnt
% umount /mnt
Reboot the system to Windows NT and copy the boot sector from the floppy
disk to the hard disk. For example, using the command line to copy the file:
C:> copy a:\bootsect.lnx c:\bootsect.lnx
It doesn't matter where on the hard drive you put the file because you'll
tell the NT loader where to find it in step 8.
Modify the attributes of the file
to remove the system and read-only attributes so you can edit it:
boot.ini is the Windows NT counterpart to /etc/lilo.conf. It
defines what operating systems the NT loader can boot.
C:> attrib -s -r c:\boot.ini
Edit boot.ini with a text editor to add the line:
This line adds Linux to the boot menu and tells the Windows NT boot
loader where to find the Linux boot sector.
You can insert the line anywhere in the [operating systems] section
of the file. Its position in the file determines where it will show up on
the boot menu when you reboot your computer. Adding it at the end, for
example, results in a boot.ini file that looks something like this
(the second multi(0) entry is wrapped to fit in the margins of
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Server Version 4.00"
multi(0)disk(0)rdisk(0)partition(1)\WINNT="Windows NT Server Version 4.00
[VGA mode]" /basevideo /sos
If you want Linux to be the default operating system, modify the default= line to say:
Rerun attrib to restore the system and read-only attributes:
C:> attrib +s +r c:\boot.ini
Now you can shut down Windows NT and reboot; NT will prompt you with a
menu that looks something like this:
OS Loader V4.00
Please select the operating system to start:
Windows NT Workstation Version 4.00
Windows NT Workstation Version 4.00 [VGA mode]
Select Linux, and the NT loader reads the Linux boot sector and
transfers control to LILO, on the Linux partition.
If you later modify /etc/lilo.conf or rebuild the kernel, you need to
rerun the lilo command, create a new bootsect.lnx file, and
replace the version of bootsect.lnx on the Windows NT partition with
the new version. That is, you need to rerun steps 2-6.
If you have any problems or you simply want to remove LILO later, you
can reverse the installation procedure: boot to Windows NT, change the
system and read-only attributes on boot.ini, reedit
boot.ini to remove the Linux entry, save the file, restore the system
and read-only attributes, and remove the Linux boot sector
from the NT partition.
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