Hi everyone.

I was pretty sure booting a non-NT OS (DOS, Windows 9x, and even Linux) via NTLDR was as simple as just extracting the boot sector (the VBR) into c:\bootsect.dos and declaring something like this in c:\boot.ini:

1[boot loader]
2timeout=0
3default=C:\
4
5[operating systems]
6C:\ = "MS-DOS 6.22"

Recently, I came across Boot INI Options Reference, published back in 2006 and still available online, which lists two boot.ini options I've never used previously:

1. /WIN95
   Directs Ntldr to boot the Consumer Windows boot sector stored in Bootsect.w40. This switch is pertinent only on a triple-boot system that has MS-DOS, Consumer Windows, and Windows installed. See Microsoft Knowledge Base article Q157992 for more information.
2. /WIN95DOS
   Directs Ntldr to boot the MS-DOS boot sector stored in Bootsect.dos. This switch is pertinent only on a triple-boot system that has MS-DOS, Consumer Windows, and Windows installed. See Microsoft Knowledge Base article Q157992 for more information.

Yet, Q157992 tells nothing new except

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

What it doesn't tell in particular is now to resolve name conflicts between io.sys, io.dos, and io.w40 (and their msdos.{sys,dos,w40} and command.{com,dos,w40} counterparts) when switching from Windows 9x to DOS and vice versa.

Questions:

1. What exactly /win95dos and /win95 switches are needed for? I've successfully booted MS-DOS, Windows 9x, Linux and even Solaris/x86 like hundreds of times, w/o any extra switches. Yet, I can confirm these switches do make some difference: a Windows 98 VBR indeed can't be combined with an explicit /win95dos switch (the boot process simply doesn't go beyond the black-screen-with-a-blinking-cursor stage).
2. How do I triple-boot Windows NT 4.x/5.x, Windows 9x, and MS-DOS from the same primary partition (C:) of a single hard drive, using NTLDR? Yes I'm aware Windows 9x boot loader can boot "your previous operating system" (which happens to be MS-DOS) via Windows 9x boot menu, but how do I do that via boot.ini? Microsoft claim this is possible, they can't be mistaken, right?