Phil's webpage with the DOS starter pack at https://www.philscomputerlab.com/ms-dos-starter-pack.html
supplies downloads for mouse and CD drivers that will probably work for you,
but note that Phil says
This starter pack has been tested with MS-DOS 6.22 and 7.1. DO NOT install this starter pack in Windows 95 or 98 MS-DOS mode. It is meant for pure MS-DOS only.
That means you'll have to alter the config.sys and autoexec.bat he's supplied if you're using a default Windows 95 or 98 installation.
If you want to use Phil's customized DOS 7.1 installation (without Windows 95/98) he has a video
https://www.youtube.com/watch?v=N2SPlHzAcSI
Keep in mind you'll need DOS drivers for your sound card too.
Phil doesn't supply those on the starter pack webpage because they vary with the sound card.
Do you know what sound card your computer has?
Phil is using the line
LH C:\DRIVERS\CTMOUSE.EXE /R2
That means DOS expects to find the ctmouse.exe file in your C:\drivers folder
If you put ctmouse.exe in a different folder, adjust the path.
/R2 is a mouse sensitivity switch and whether you need the /R2 depends on the mouse you're using.
Phil uses videccd.sys as the CD driver.
The CD driver is loaded in config.sys and needs a corresponding line with MSCDEX in autoexec.bat.
Phil is using
DEVICEHIGH=C:\DRIVERS\VIDECDD.SYS /D:OPTICAL in config.sys and
LH C:\DOS\MSCDEX.EXE /D:OPTICAL in autoexec.bat
Just as with the mouse driver, the VIDECCD.SYS file needs to be where the line says it is.
If you put VIDECCD.SYS somewhere other than the C:\drivers folder -- adjust the line in config.sys so it points to the correct location.
The /D:OPTICAL associates the driver line in config.sys with the mscdex line in autoexec.bat, and the part after /D: can be pretty much anything, but has to match.
So you'll find samples on the Internet with something like /D:BANANA
DEVICEHIGH=C:\DRIVERS\VIDECDD.SYS /D:BANANA in config.sys and
LH C:\DOS\MSCDEX.EXE /D:BANANA in autoexec.bat
and I think the Windows 98 emergency boot floppy uses /D:MSCD001
DEVICEHIGH=C:\DRIVERS\VIDECDD.SYS /D:MSCD001 in config.sys and
LH C:\DOS\MSCDEX.EXE /D:MSCD001 in autoexec.bat
/D: is not the drive letter -- it's a switch.
If you're using Start-> Shut Down -> Restart in MSDOS mode in Windows 95/98, the mouse driver and MSCDEX line go in C:\Windows\dosstart.bat instead of C:\autoexec.bat. If you put the lines in C:\autoexec.bat, Windows 98 may move the lines to C:\Windows\dosstart.bat automatically.
If you're using a default installation of Windows 95 or 98, you may have noticed that you have no C:\DOS folder, so the MSCDEX line would be adjusted to C:\Windows\Command
LH C:\Windows\Command\MSDCEX.EXE /D:OPTICAL