Microsoft KB Archive/103973

Removing a Windows NT Boot Sector or NTFS Primary Partition

PSS ID Number: Q103973 Article last modified on 09-07-1993

3.10 WINDOWS

This article details procedures that enable you to remove a Windows NT boot sector from your system. Before you begin, make sure you know where Windows NT is installed, how much of it you want to remove, and how your hard disk drive is partitioned and formatted. Then, go to one of the following sections: - Removing Windows NT from the Boot Sequence - Removing a Primary NTFS Partition

Removing Windows NT from the Boot Sequence
There are two ways to remove the Windows NT boot sector from your computer: - If you want to return to your original MS-DOS configuration, boot MS-DOS and type “sys c:” (without the quotation marks). This command replaces the Windows NT boot sector with the MS-DOS boot sector, and allows your computer to boot straight into MS-DOS. The following files are left in the root directory and can be deleted after you perform the SYS operation: PAGEFILE.SYS BOOT.INI NTLDR NTDETECT.COM NTBOOTDD.SYS NOTE: NTBOOTDD.SYS is installed only if you have a SCSI Host Adapter installed in Windows NT. - If you want to leave NTLDR on the disk, you can boot MS-DOS without prompting by changing the startup operating system and time-out value. To do so, choose the System icon in the Control Panel, select MS-DOS in the Startup box, and type “0” (without the quotation marks) in the Show List For box. NOTE: If the primary partition was converted to Windows NT file system (NTFS), the only way to return to starting MS-DOS only is to reformat the drive and reinstall MS-DOS. See the next section if this is the case.

Removing a Primary NTFS Partition
In general, attempts to modify the primary, bootable, NTFS partition fail for the following reasons: - MS-DOS versions 5.0 and 6.0 do not recognize an NTFS partition. The MS-DOS FDISK program reports an NTFS partition as an OS/2 high-performance file system (HPFS) partition. - You cannot modify or delete an NTFS primary partition within itself. To delete or modify a primary NTFS partition, perform any one of the following four procedures: - Start MS-DOS version 6.0 from a floppy disk and press RETURN to continue installing MS-DOS 6.0. When prompted to do so, choose “Remove files.” - Initiate Windows NT installation from floppy disks or CD-ROM. When prompted to do so, choose “P” to remove the partition. - Use the DELPART utility to delete the NTFS partition. DELPART is provided in the Microsoft Windows NT Resource Kit. Note that DELPART cannot delete a logical drive in the extended partition. - Start OS/2 version 1.x from a floppy disk and run its Fdisk program. To remove the partition, specify the /D option. - Use Disk Administrator and the MS-DOS FDISK command in the following procedure: NOTE: To use this procedure you must have a bootable MS-DOS floppy disk and the ability to boot into MS-DOS from the Operating System (OS) Loader. CAUTION: If the Windows NT system files are stored on your primary partition, you will need to reinstall Windows NT after performing this procedure. 1. Start Disk Administrator and select the primary NTFS partition. 2. From the Partition menu, choose Drive Letter and select “Do not assign a drive letter.” 3. Exit Disk Administrator and shut down Windows NT. 4. Choose MS-DOS for your operating system. 5. At the MS-DOS command prompt, run the FDISK command. 6. FDISK should recognize the primary NTFS partition as an HPFS partition. Delete the primary partition. You can now partition and format the primary partition using the FDISK and FORMAT commands.

Additional reference words: 3.10 KBCategory: KBSubCategory: STP FILSYS Copyright Microsoft Corporation 1993.