I do not recommend installing old DOS on a Win95 machine at all.
   Win95's included MS-DOS 7.0, in Single Mode, can run anything
   that previous versions of DOS can, including Windows 3.1 or Windows
   for Workgroups! If you have to run old DOS programs that don't run in
   DOS sessions in Win95, check out the Running MS-DOS Games page.
   
   With that aside, to install the missing utilities that DOS 7.0
   blatantly forgot from DOS 6.22:
    1. Find the \OLDMSDOS directory on the Win95 CD-ROM in
       \OTHER\OLDMSDOS.
    2. Run the install.bat from that directory, within Win95.
    3. When asked to, shut down and re-start your computer. This is
       because the old DOS programs are really from DOS 6.22, and the
       batch file SETVER's them to that version of DOS.
       
   You'll find other old DOS toys in the directories of \OTHER, including
   MSD and the Central Point version of MSBACKUP.
   
   To install Windows 3.1 or Windows for Workgroups on a system running
   Win95:
    1. Find your original Win 3.1/WFWG disks of course. Silly.
    2. Exit to Single mode DOS by Start Menu/Shut Down, and "Restart
       computer in MS-DOS Mode".
    3. Make copies of any config.sys or autoexec.bat you have (You
       shouldn't have these anyway!)
    4. Run Setup from your Win 3.1 disk 1 and install normally, into any
       directory that Win95 isn't in! Like C:\WIN31
    5. When Setup finishes, choose the option to Exit to DOS.
    6. Make copies of any changes that Win 3.1 Setup made to your
       config.sys and autoexec.bat, and restore your original versions
       of these files. You'll need these copies later on!
    7. Type exit to go back into Win95.
    8. Find win.com in your Win 3.1 installation, right-click on that
       file, and hit "Properties".
    9. Hit the Program tab, hit Advanced, hit "MS-DOS Mode", hit "Specify
       new MS-DOS Configuration."
   10. In the empty spaces below, copy & paste the text from the saved
       config.sys and autoexec.bat that Win 3.1 Setup modified. CTRL-V
       works in these text boxes to paste text from the clipboard in. Add
       a LOCK C: to the end of the special autoexec.bat (for 32-bit disk
       and file access, if you wish to use it).
   11. Modify the resulting text entries so you use the right versions of
       these files. Finally OK everything.
       
   Use Win95 versions (C:\WIN95\.....) of these files:

     * HIMEM.SYS
     * EMM386.EXE
     * SMARTDRV.EXE
       
   Use Win 3.1 versions (C:\WIN31\... or C:\WINDOWS\...) of these files
   (Only relevant to WFWG actually)

     * IFSHLP.SYS
     * NET START
     * MSCDEX (If you share a CD-ROM via WFWG)
       
   When you double-click on win.com here, or on its resulting PIF file
   (Shortcut to MS-DOS program), your computer will restart using this
   special DOS configuration. When you exit Win 3.1, Win95 will restart.
   Trust me; this is the absolute best way to get Win 3.1 working on a
   Win95 machine, if you don't have an older DOS already installed.
   
   NOTE: Windows for Workgroups, in particular, will ask you to "Restart
   Computer" sometimes. This is fine; Win95 won't try to re-start because
   a line in the special AUTOEXEC.BAT (WIN.COM /EX) won't execute, and
   your computer will re-start still using the special DOS configuration.
   The only way to get back into Win95 safely, is to exit Win 3.1 with
   Program Manager (File/Exit Windows).
   
   Also notice, that you'll find files named CONFIG.W40 and AUTOEXEC.W40
   in your hard drive. These files are Win95's DOS configuration. Leave
   them alone! Don't touch them! Win95 copies these back to CONFIG.SYS
   and AUTOEXEC.BAT when you finish with Win 3.1.
   
   And don't try to install old DOS on a Win95 machine. Just don't.
   You'll regret it. And don't ask me why. You'll regret hearing why.
   
   4.00.950B users will discover a VERY ANNOYING message when they try to
   run Win 3.1 under 950B's version of DOS (MS-DOS 7.1): "The version of
   MS-DOS you are running is incompatible with this version of Windows.
   Your system had been halted." (grrr... this string is hard-wired into
   IO.SYS so I think this is a deliberate hack on MS's part)