How to Triple Boot to Windows NT, Windows 95/98, and MS-DOS

This article describes how to set up a computer so that the user can go directly to Windows NT, Windows 95/98, or MS-DOS by making a selection from the Boot.ini, without any need for Windows 95/98 multiple boot support.

Windows 98 or Windows 95 should not be installed in the same partition as Windows NT; the shared Program Files folder can cause problems with interactions between Microsoft Internet Explorer and Microsoft Outlook Express on these operating systems.

Also, if you are using both FAT32 and NTFS volumes, the NTFS partition should be on a logical drive letter that preceeds the FAT32 partition drive letter. If this is set up the other way around, Windows NT will not find the boot partition (where the system files are located).

This information applies to x86 processors only.

Follow these steps to enable triple boot support:

1. Install MS-DOS.
2. Install Windows NT.
3. Remove the read-only, hidden, and system attributes of Bootsect.dos by typing and running the following line from the command prompt: attrib -r -h -s bootsect.dos.
4. Copy the boot sector for MS-DOS by typing and running the following line from the command prompt: copy c:\bootsect.dos c:\bootsect.sav.
5. Boot to MS-DOS and install Windows 95/98.
6. Repair the Windows NT boot sector as Windows 95/98 has over-written the boot sector. This will also create a new Bootsect.dos for Windows 95/98. For additional information, please see the following article in the Microsoft Knowledge Base:
   104429  (http://support.microsoft.com/kb/104429/EN-US/ ) Installing MS-DOS Version 6.2x After Windows NT Is Installed
7. Remove the read-only, hidden, and system attributes from the Windows 95/98 Bootsect.dos by typing and running the following line from the command prompt: attrib -r -h -s bootsect.dos.
8. Rename the Windows 95/98 boot sector from C:\Bootsect.dos to C:\Bootsect.w40.
9. Rename the MS-DOS boot sector from C:\Bootsect.sav to C:\Bootsect.dos.
10. Remove the read-only attribute from boot.ini by typing and running the following line from the command prompt: attrib -r boot.ini.
11. Modify Boot.ini using any text editor, such as Edit or Notepad, by adding the following lines:
    [Operating Systems]
    c:\bootsect.dos="MS-DOS v6.22" /win95dos
    c:\bootsect.w40="Windows 95/98" /win95

You should now see the additional choices of "Windows 95/98" and "MS-DOS v6.22" when you start Windows NT.

The new switches, /win95dos and /win95, are needed so that Windows NT can emulate the multiple boot process of Windows 95/98.

This article contains information about using Windows NT with a configuration that has not been tested and is not supported by Microsoft. If the steps described in this article do not function properly, use a supported configuration.

If Windows NT is going to be on the same partitions as MS-DOS and/or Windows 95/98, the partition must be an MS-DOS partition. Windows 95/98 FAT 32 partitions will not work with MS-DOS and Windows NT.

Using NTFS or FAT32 partitions will require different partitions for each operation system. The ARC path in the Boot.ini file will need to be modified to reflect the different partitions.

For additional information, please see the following article in the Microsoft Knowledge Base: