Dual-Boot removal Procedures - Remove Windows or Linux

Introduction

Many users decide to take a look at Linux and load it on their PC alongside Windows in a dual boot arrangement.

Having installed Linux in a dual boot arrangement, users may have a positive or negative experience with Linux. Some of these may later on decide to uninstall / remove Linux. Others may decide to uninstall / remove Windows. There will obviously be others who decide to keep both to have the benefit of both worlds. This presents the first two groups of people with a problem leading to the question how do I remove....?

This procedure attempts to help the readers understand how to remove the unwanted OS from their PC.


I have excluded all Windows upto Win95, and WinNT from consideration due to obsolesence.
I have also excluded WinME as I have a poor opinion of it and consequently have little experience of it.

However, in general, the procedures for Win98 should apply equally to Win95 and WinME.

Similarly the procedures for WinXP should apply to Win2K and WinNT. There may be a few minor differences.

The repair procedures can be understood in more detail if you get a basic understanding of how Windows and Linux Boots up. A basic understanding of how the MBR is used by Windows and Linux is given in the file pointed to by the link below. It also contains basic information on the Linux Boot Loaders (GRUB and LILO). This includes uninstallation information in summarized form which you can use directly if you are familiar and don't care about the individual case procedures.

The Boot Process, The MBR and The Boot Loaders

Dual-Boot Configurations

Dual-Boot arrangements come in many shapes and sizes. I will list just a few for illustration.
In this list I will use Linux generically as there are too many flavours to list individually.

  1. Win98 and Linux using LILO (LInux LOader ) as the boot loader

  2. Win98 and Linux using GRUB as the boot loader

  3. WinXP and Linux using LILO as the boot loader

  4. WinXP and Linux using GRUB as the boot loader

  5. WinXP and Linux using the NT Boot Loader


Removal Process Detail

  1. Remove Linux Keep Windows.

  2. Linux Removal depends on which Boot Loader is being used:

    1. Linux removal when Linux Boot loader (LILO or GRUB) is being used.

    2. Linux removal in this case requires 2 steps:

      1. Remove the Linux Boot Loader

        1. If Linux Is still Installed and LILO is installed in the MBR as BOOT Loader

          1. Boot into Linux

          2. Open a terminal session and su as root.

          3. Run the lilo command using the -u or the -U option. The device name (optional) must be the second parameter.
          4. The only difference between the two options is that:

            lilo -u --- (-u checks the time stamp on the current MBR)
            lilo -U --- (-U does not check the time stamp at all)
            /sbin/lilo -u --- (This specifies the full pathname in case it is not declared)
            /sbin/lilo -U

            If LILO is installed to the MBR of the master drive on the primary IDE controller, type

            lilo -u /dev/hda --- where dev=device directory, hd=IDE hard disk, a=master on the primary IDE channel.

            If you want to use the command on a SCSI drive, type

            lilo -u /dev/sda --- where sd=SCSI drive and a=first drive in the SCSI chain.

            If the drive has multiple partitions, indicate the partition from which you want to uninstall LILO by adding the number that corresponds to the partition number on the drive, starting the count at 1 (not 0).

            For example, to remove LILO from the first partition of the first SCSI drive, type:
            lilo -u /dev/sda1 --- (Note that sda is not related to the SCSI ID number).

        2. If Linux Is still Installed and GRUB is installed in the MBR as BOOT Loader

        3. GRUB has no uninstaller. This is what the GRUB people say about this lack of it:
          "There is no concept uninstall in boot loaders, because if you uninstall a boot loader, an unbootable machine would simply remain. So all you need to do is overwrite another boot loader you like to your disk, that is, install the boot loader without uninstalling GRUB."
          However LILO has an uninstall feature that restores the MBR that was there before LILO. So come on GRUB why can't you?

          Uninstalling the Boot Manager GRUB from the MBR

          Using a DOS or Windows 9x/ME Boot Floppy

          In case you have DOS or Windows 9x/ME on your system, you can use fdisk for this purpose.

          1. Create a DOS or Windows 9x/ME start-up disk

          2. Boot the computer with the DOS or Windows 9x/ME start-up disk

          3. Execute fdisk as follows:
          4.    fdisk /MBR
               The MBR will be rewritten and GRUB will be uninstalled. 
            
               NOTE: The procedure, shown above, is not supported by Microsoft
                     (although they recommend it themselves) and is performed
                     strictly at the discretion of the user.
                     No liability for lost or corrupted data accepted.
            
               IMPORTANT: Running fdisk /mbr removes the disk signature from the MBR.
                          If the drive is a member of a Windows fault tolerance set,
                          the drive is no longer recognized as a member of that set.

          Using Windows XP

          In Windows XP, you can uninstall GRUB as follows:


          1. Boot from the Windows XP CD and press the "R" key during the setup in order to start the Recovery Console.
          2. Select your Windows XP installation from the list and enter the administrator password.
          3. At the input prompt, enter the command FIXMBR and confirm the query with "y".
          4. The MBR will be rewritten and GRUB will be uninstalled. press "exit" to reboot the computer.

          Using Windows 2000

          In Windows 2000, you can uninstall GRUB as follows:

          1. Boot from the Windows 2000 CD and press the "R" key during the setup and then the "K" key in the following menu in order to start the Recovery Console.
          2. Select your Windows 2000 installation from the list and enter the administrator password.
          3. At the input prompt, enter the command FIXMBR and confirm the query with "y".
          4. The MBR will be rewritten and GRUB will be uninstalled. press "exit" to reboot the computer.

        4. If Linux Is Not Still Installed

        5. This situation arises mainly because the user has (without thinking) repartitioned the hard drive and deleted the Linux partitions with the aim of reclaiming them for Windows. However, the user has failed to realise that the Linux Boot Loader (LILO / GRUB) is still installed. The first hint of something being wrong is when attempting to boot to windows strange effects are observed as the Linux Boot loader tries to load (for example if you are using LILO, the boot process stops at: LI). This is because when you removed your Linux filesystems, you also removed the additional boot loader code (the "secondary boot loader").

          To get over this problem, you need to remove the Linux Boot loader from the MBR.
          To do this follow the same procedure as the one defined above for removing the GRUB boot loader.


      2. Delete the Linux Partitions
      3. This is an area that people often have difficulty with. Particularly when you have Linux partitions that are contained in the extended partition. There are a number of different ways of deleting partitions and you need to be aware of them in order to use the one that most appropriately fits your given case. Some are complex and some simple. Select the simpler procedure if it works to minimise the steps you have to go through.

        The different procedures for partition removal are shown here:.
        Partition Removal Information. I recommend using the Ranish Partition Manager method.

    3. Linux removal when the Windows NT Boot Loader is being used.

    4. Linux removal in this case requires 2 steps:

      1. Delete the Linux Partitions

      2. The different procedures for partition removal are shown here:.
        Partition Removal Information. I recommend using the Ranish Partition Manager method.

      3. Remove the Linux from the NT Boot Loader menu

      4. Boot into Windows, Edit your boot.ini file and remove Linux from your list of OSes to boot.

        Editing the boot.ini file

        To edit your boot.ini file, open the root partition of your hard drive (normally C:\) and find the file called "BOOT.INI".
        It is normally a read only system file with hidden attributes set. You may need to unhide system files.

        You will also need to enable it to be edited as follows:
        Folder > Options. Right-click on the file, select Properties and uncheck "Read-only" then click OK.

        You may wish to take a backup of the file at this point to allow you to restore if you experience problems.

        Open the file in Notepad and under the [operating systems] section you will find a list of all the installed operating systems.

  3. Remove Windows Keep Linux.

  4. Windows Removal depends on which Boot Loader is being used:

    1. Windows removal when Linux Boot loader (LILO or GRUB) is being used.
      Windows removal in this case requires 2 steps:

      1. Delete the Windows Partitions

      2. The different procedures for partition removal are shown here:.
        Partition Removal Information. I recommend using the Ranish Partition Manager method.

      3. Remove the option to boot windows from the Linux Boot Loader

        • If the Linux Boot Loader used is LILO, then:

        • Update the LILO configuration information to remove Windows as a bootable option.

          If you are doing this manually then:


          1. Edit the /etc/lilo.conf file and delete the Windows entry.

          2. Update LILO (/sbin/lilo -v)

        • If the Linux Boot Loader used is GRUB, then:

        • Edit the /boot/grub/grub.conf file and delete the Windows entry.

        To understand the GRUB and LILO config file formats. Look up Linux Boot Loader Config Files.

    2. Windows removal when the Windows NT Boot Loader is being used.

    3. Windows removal in this case requires 2 steps:

      1. Replace the NT Boot Loader with a Linux Boot Loader

      2. Boot into Linux and update your configuration to load the Linux Boot Loader of your choice into the Master Boot Record (MBR).

      3. Delete the Windows Partitions

      4. The different procedures for partition removal are shown here:.
        Partition Removal Information. I recommend using the Ranish Partition Manager method.

        Note:
        The Windows partitions can either be deleted using the procedure above, or used as is as a FAT32 storage area for Linux.
        If you delete the partitions then you can use the Linux fdisk facility to set up new Linux partitions.


© MAK 2004
End of Document