Uninstalling Windows® 2000
Updated: October 1, 2000


Uninstalling Windows 2000 is more of an issue of how and where you installed it on the drive than anything else. There are three general installation methods, stand-alone, upgrading over a previous operating system and a dual-boot configuration. There are also other factors to be considered, such as third party programs that have been installed as well as data and document issues.

The procedures set forth below were designed around a general need to remove or uninstall Windows 2000 as quickly as possible without substantial focus on data backup and or recovery. However, before you begin any of the processes outlined, you should have at least some knowledge of how to backup and recover any data and or documents that you may need for use elsewhere.

It should be rather obvious to you that uninstalling or removing a stand-alone installation of Windows 2000 from a computer where there was no upgrade or dual-booting involved is rather straight forward. Just backup or transfer your documents and other necessary data files to another disk, tape or other storage device, and then format the drive and install the operating system of choice. Do not attempt to save programs or program settings as they will not be transferable to, or usable by, any other operating system. The following will focus on most installation situations that you may face.

Main Contents


Introduction:

Regardless of whether you are removing a Windows 2000 installation that was an upgrade or installed as a dual-boot environment, understand that the uninstall process is not merely one of removing the Windows 2000 files. The following should provide you with a basic understanding of what files are installed and their possible locations. Remember, when this operating system is installed, it provides choices as to where various files (other than boot files) are installed!

Critical installation files:

First active partition (usually drive C:):

No matter where you have installed Windows 2000, the installation files are always located on the first active partition, and Windows 2000 refers to this partition as the system partition. There is a second group of files and directories, and those will be found in the boot partition, another Windows 2000 term. Take note of the two terms, "boot partition" and "first active partition". You will find that the majority of the installation files are located in the systemroot directory (winnt) on the active partition that you specified during installation process. On that same partition will also be located your Documents, Settings and Program File directories, along with pagefile.sys (swap file) and hiberfil.sys (system hibernation file). Only removing these groups of files will not completely remove Windows 2000!

Another important part of Windows 2000 installation is the NT boot loader. This is special program that that lets you choose whether to boot to Windows 2000 or to another operating system. Every time you start your computer, the boot loader starts and shows you the boot menu. While this program is located in ntldr, merely deleting it won’t finish a removal of Windows 2000. The "ntldr" is embedded in the hard drives boot sector. You must overwrite the boot sector that loads this program in order to completely remove it.

Uninstalling Windows 2000
Under Differing Installation Scenarios


CONTENTS

Part I
Section A - Dual booting Windows 2000 and Windows 95/98
Section B - Dual booting Windows 2000 and Windows NT
Section C - Windows 2000 as the only operating system on the computer

Part II
Introduction to the NT Boot Loader
Boot Files
Removing files or deleting/formatting partitions?



PART I

Part I consists of step-by-step procedures for removing Windows 2000 from your hard drive, and is broken down into three sections. Section A is for dual booting Windows 2000 with Windows 95/98, Section B is for dual booting Windows 2000 with Windows NT 4.0. (Be careful to uninstall the correct operating system) and Section C describes the removal of Windows 2000 if it is the only operating system installed.

Section A - Dual booting Windows 2000 and Windows 95/98

Windows 2000 on the same partition as Windows 95/98

  1. Boot to Windows 95/98 [with win9x boot disk]
  2. Type sys c: at the MS-DOS prompt
  3. Remove/Delete the boot.ini, bootsect.dos, ntldr, ntdetect.com files and ntbootdd.sys (if exists) from c:\
  4. Delete the pagefile.sys file (usually on c:)
  5. Delete hiberfil.sys file (if exists)
  6. Delete the winnt directory (the directory you installed Windows 2000)
  7. Delete the Documents and Settings directories

Windows 2000 on the different FAT or FAT32 partition than Windows 95/98

  1. Boot to Windows 95/98 [with a Win9x boot disk]
  2. Type sys c: at the MS-DOS prompt
  3. Remove/Delete the boot.ini, bootsect.dos, ntldr, ntdetect.com files and ntbootdd.sys (if exists) from c:\
  4. Delete the pagefile.sys file (usually on c:)
  5. Delete the hiberfil.sys file (if exists)
  6. Delete the winnt directory (the directory you installed Windows 2000)
  7. Delete the Documents and Settings directories
  8. Delete Program Files directory
  9. Delete temp directory

Windows 2000 on the different FAT or FAT32 partition as Windows 95/98

  1. Boot to Windows 95/98 [with Win9x boot disk]
  2. Type sys c: at a MS-DOS prompt
  3. Remove/Delete the boot.ini, bootsect.dos, ntldr, ntdetect.com files and ntbootdd.sys (if exists) from c:\
  4. Delete the pagefile.sys file (usually on c:)
  5. Format the Windows 2000 partition
    * Make sure you copy all of the data files you need to different partition!

Windows 2000 on a NTFS partition and Windows 95/98 on FAT Partition

  1. Boot with either a Windows 2000 CD or the Windows 2000 boot disks
  2. If the setup program asks if you want to repair the existing Windows 2000 installation, or do a fresh installation of Windows 2000, select fresh install.
  3. When setup asks you to select a partition, remove the Windows 2000 partition
  4. Create new FAT partition(s) instead
  5. Exit setup program (F3) without installing
  6. Boot to win 95/98 [with win9x boot disk]
  7. Type sys c: at the DOS prompt.
  8. Delete the boot.ini, bootsect.dos, ntldr, ntdetect.com files and ntbootdd.sys (if exists) from c:\
  9. Delete the pagefile.sys file (usually on c:)
  10. Delete the hiberfil.sys file (if exists)

Section B - Dual booting Windows 2000 and Windows NT

  1. Boot to Windows NT
  2. Format the Windows 2000 partition (copy all important files to other partition)
  3. Remove the read-only attribute from the boot.ini file
  4. Open the boot.ini file
  5. Remove the one line that references Windows 2000
  6. Save and close the boot.ini file.

Sample BOOT.INI before:
[boot loader]
timeout=5
default=multi(0)disk(0)rdisk(1)partition(1)\W2K_PRO

[operating systems]
multi(0)disk(0)rdisk(1)partition(1)\W2K_PRO="Microsoft Windows 2000 Professional" /fastdetect
multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Workstation Version 4.00"
multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Workstation Version 4.00 [VGA mode]" /basevideo

Sample BOOT.INI after editing:
[boot loader]
timeout=5
default=multi(0)disk(0)rdisk(0)partition(2)\WINNT [operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Workstation Version 4.00"
multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT Workstation Version 4.00 [VGA mode]" /basevideo

Modifications:

Section C - Windows 2000 as the only operating system on the computer

Windows 2000 on NTFS, FAT32 or FAT partition

  1. Boot with either a Windows 2000 CD or the Windows 2000 boot disks.
  2. If the setup program asks if you want to repair the existing Windows 2000 installation or do a fresh installation of Windows 2000, select fresh install.
  3. When setup asks you to select partition, remove the Windows 2000 partition or any other partitions you like.
    Exit the setup program (F3) without installing.
  4. If you had Windows 2000 installed on another partition other than C:, then delete the boot.ini, bootsect.dos, ntldr, ntdetect.com file and ntbootdd.sys file (if exists) from C:\

Windows 2000 on FAT partition

  1. Boot to Windows 95/98 [with win9x boot disk]
  2. Type sys c: at an MS-DOS prompt
  3. Remove the boot.ini, bootsect.dos, ntldr, ntdetect.com files and ntbootdd.sys (if exists) from c:\
  4. Delete the pagefile.sys file (usually on c:)
  5. Delete the hiberfil.sys file (if exists)
  6. Delete the winnt directory (the directory you installed Windows 2000)
  7. Delete the Documents and Settings directories
  8. Delete the Program Files directory
  9. Delete the temp directory

Windows 2000 on FAT

  1. Boot to Windows 95/98 [with win9x boot disk]
  2. Type sys c: at an MS-DOS prompt
  3. Remove the boot.ini, bootsect.dos, ntldr, ntdetect.com files and ntbootdd.sys (if exists) from c:\
  4. Delete the pagefile.sys file (usually on c:)
  5. Format the Windows 2000 partition.
    * Make sure you copy all data files you need to different partition!!!

PART II

Introduction to the
NT Boot Loader


When removing Windows 2000 from a dual boot system with Windows 95/98, one of the most important steps is removing NT Boot Loader.

The NT Boot Loader is special program that allow you to boot to multiple operating systems, and Microsoft originally included it in Windows NT to allow users to dual boot Windows NT with DOS and OS/2, and later with Windows 95/98. Although not officially supported, it also works with Linux. When you start your computer, the NT Boot Loader displays all available operating systems and lets you choose the one you wish to work with.

Now, let see how all of this works:

When you first start your computer it goes through POST (Power On Self Test). Then the BIOS read the first sector on you primary (master) hard drive. This sector is referred to as the MBR (Master Boot Record) and contains four tables that describe up to four primary partitions. Just as the BIOS is transferring control to the MBR, it first scans all of the tables to find the active partition. Operating systems can start only from an active partition and only one partition can be set as active at one time. When the MBR finds the active partition it transfers control to its first sector called the Partition Boot Sector.

The boot sector of Windows 2000 contains a small portion of code that interprets the partitions file system. This is not the whole driver for the file system, just a small portion of the code that interprets the structure of the underlying file system and that can read the NTLDR file.

The code in the Partition Boot Sector then calls NTLDR. NTLDR then switches the system to Protected Mode and enables Paging. Next, NTLDR reads the BOOT.INI file and displays NT loader menu, which then enables the user to select the operating system to be booted. If the user selects to boot to Windows 95/98, NTLDR opens bootsect.dos, which contain the previous boot sector that enables Windows 95/98.

When removing Windows 2000 and it’s NT boot loader you have to replace the Windows 2000 boot sector with a Windows 95/98 boot sector. To do this, you need to use the sys (sys c:) command from Windows 95/98. This will cause the Windows 2000 boot sector to be over-written, thereby enabling the system to boot directly to Windows 95/98.

Boot Files

Windows 2000 places important files on its system partition. This partition is the active partition from where the operating system is to be loaded. As noted above, Windows 2000 needs three files to run the system, NTLDR, BOOT.INI and bootsect.dos. Apart from these files, other files are located on the system partition. These files are ntdetect.com and sometimes ntbootdd.sys. Ntdetect.com collects system information during the boot process, and ntbootdd.sys contains a SCSI driver. If you want to completely remove Windows 2000 you have to remove all these files.

Removing files or deleting/formatting partitions?

After replacing the boot sector the system will boot to Windows 95/98, but Windows 2000 files still occupy hundreds of MB on the hard drive. When removing these files and directories, there are options to consider, (A) just delete the files, or (B) reformat the entire partition. Each solution has its shortcomings.

Just Deleting Files:

Users can selectively delete files. This option is welcome when we have a lot of user data on the boot partition (not always a wise choice) and want to remove only Windows 2000 directories, and it uses a lot of them. Apart from the default installation directory (usually winnt) there may be a lot of different directories depending on the Windows 2000 version, Professional as opposed to Server. New to Windows 2000 are the Documents and Settings directories that contains user files and profiles. Windows 2000 also creates a temp directory for temporary files.

On NTFS volumes, Windows 2000 also creates two super-hidden directories, Recycler and System Volume Information. Obviously, Recycler is the directory that contains deleted files. As you can see, it may be easier to reformat the entire partition. The only drawback would be to make sure that you copy important data files to another partition. When deleting files make sure you find and delete pagefile.sys. If you have enabled hibernation also delete hiberfil.sys.

 


This guide to uninstalling Windows 2000 under various circumstances has been provided "as is" and for no other purpose than to provide insight as to some of the procedures that must be followed in order to remove Windows 2000. In essence, these are the procedures that we have followed successfully, although your mileage may vary.

Copyright ©1999-2005 DEW Associates Corporation. All rights reserved.