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Q116358: Upgrading to Windows 95 May Disable Windows NT Boot Sector

Article: Q116358
Product(s): Microsoft Windows 95.x Retail Product
Version(s): 95
Operating System(s): 
Keyword(s): kbsetup win95
Last Modified: 17-DEC-2000

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The information in this article applies to:

- Microsoft Windows 95 
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SYMPTOMS
========

When you install Windows 95 on a computer running Microsoft Windows NT, The
Windows NT boot record (Ntldr) may be lost.

CAUSE
=====

This problem can occur for either of the following reasons:

- You are using Small Computer System Interface (SCSI) hard disks on Micro
  Channel Architecture (MCA) computers.

- You started the computer with an MS-DOS disk before installing Windows 95,
  thereby bypassing the Windows NT boot loader.

RESOLUTION
==========

You can use the Windows NT Repair Disk that was created when you installed
Windows NT to re-create the Windows NT boot record.

MORE INFORMATION
================

On an MCA computer, the highest SCSI ID must be the boot drive. The boot drive
of an Industry Standard Architecture (ISA) or Extended Industry Standard
Architecture (EISA) computer is SCSI ID 0. Because of this, all physical hard
disks on an MCA computer are listed, but they are disabled (or not listed) on an
ISA or EISA computer (unless they are IDE hard disks).

When you install Windows 95, it installs the boot record on the bootable drive.
If the physical hard disks are listed in CMOS (as with MCA computers), any
remaining boot records are removed. Since the boot record on a SCSI hard disk in
an ISA or EISA computer is handled by a device driver, they are not listed in
the CMOS, and Windows 95 does not remove them.

For information about restoring dual-boot capabilities after installing Windows
95, please see the following article in the Microsoft Knowledge Base:

  Q136547 Restoring Windows NT Dual Boot After Installing Windows 95

Additional query words: winnt

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Keywords          : kbsetup win95 
Technology        : kbWin95search kbZNotKeyword3
Version           : 95
Issue type        : kbprb

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