DOCUMENT:Q240718  08-AUG-2001  [winnt]
TITLE   :Previous OS Disabled by Setup and Is Not Listed on Boot Menu
PRODUCT :Microsoft Windows NT
PROD/VER:winnt:4.0
OPER/SYS:
KEYWORDS:kbsetup kbui

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The information in this article applies to:

 - Microsoft Windows NT Workstation version 4.0 
 - Microsoft Windows NT Server version 4.0 
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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
   ============================

   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
   ============================

   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 this to be 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

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Keywords          : kbsetup kbui 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400
Version           : winnt:4.0
Issue type        : kbprb

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