Microsoft KB Archive/240718

= Previous Operating System Disabled by Setup and Is Not Listed on Boot Menu Afterwards =

Article ID: 240718

Article Last Modified on 11/1/2006

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APPLIES TO


 * Microsoft Windows NT Workstation 4.0 Developer Edition
 * Microsoft Windows NT Server 4.0 Standard Edition

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This article was previously published under Q240718



SYMPTOMS
During Windows NT 4.0 Setup, there are several times when choices must be made about the partition information on the disk, and the location for the Windows NT installation. If your computer is dual-booting with an operating system (such as Microsoft Windows 98) that has a file system that is not supported, Windows NT may generate the following error message:

Windows NT Workstation Setup

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The partition you have chosen is not recognized by Windows NT.

Setup cannot install Windows NT onto this partition. However you can return to the previous screen and delete the partition, and then select the resulting unpartitioned space. Setup will automatically create a new partition onto which you can install Windows NT.

Also, if the partition you are installing Windows NT on must first be deleted and a new one created, you receive the following message after the partition is selected:

Windows NT Workstation Setup

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To complete Windows NT installation, Setup must temporarily disable the operating system that currently starts when your computer is powered on or restarted. That operating system will not be destroyed, uninstalled, or otherwise altered as a result of being disabled by Setup.

You can re-enable the operating system that Setup disables by using the Disk Administrator to mark its partition as active. Refer to your System Guide for more information about Disk Administrator.



CAUSE
This problem occurs when you install Windows NT on a partition where the current operating system uses a file format that is not supported by Windows NT and is marked as Active in the partition tables.



RESOLUTION
To work around this problem note that when configuring a computer for dual-booting, the primary startable partition should be one that is common to both operating systems. In this example the only operating system that is common to Windows 98 and Windows NT 4.0 is FAT16. A small FAT16 partition can serve as the Primary DOS partition and can serve as the container for the startup files for both operating systems.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.



MORE INFORMATION
If the installation in the above example is completed, Windows NT creates a new Primary DOS partition. Because of this, there may be more than one Primary DOS partition on this computer. It will then be possible to use Disk Administrator to set the previous partition as Active and permit the previous operating system to boot. However, doing so makes it difficult to start Windows NT on the computer.

Additional query words: fat32 fat-32 windisk

Keywords: kbprb kbsetup kbui KB240718

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