Triple Operating System
When Windows crashes and the emergency disks don't help then it is often useful to have a way to copy or rename files in DOS and then return to Windows. But it is not often clear how to install Windows while retaining a full version of DOS. Also, If you try to install Windows 95 over the top of Windows 3.1 it will insist that 3.1 be removed first. This is strange behavior from the authors of these programs considering these programs can quite happily co-exist and it is none of their business how we set up our software in the first place.
This tutorial describes how to install a triple OS (operating system). These OS's are DOS (any version up to 6.22) and Windows 3.x and Windows 9x (It does work for Windows 98;) A friend of mine who returned from a computer store after having them fix a CD problem and reinstalling Windows was told that even running the original DOS was impossible, despite the fact that he had had "real" DOS running on his system for six months; (it is a P3). Maybe they should try an install without their OEM (Original Equipment Manufacturer) install disks.
You will need:
A good knowledge of installing an operating system from scratch.
The OS installation disks and CDs.
A DOS CD-ROM installation disk (if you don't install it manually.)
The drivers (on disk) for your sound card, video card, etc.
To back up everything you want to keep to another drive or disks.
To take full responsibility.
If you don't have or agree to any of the above or have never installed an operating system (especially your current one) before then I would suggest that you leave trying this type of installation until later when you are more prepared.
I shall assume that you have done a full install of these operating systems before and just need to know how to make them work together.
If you already have "real" DOS (version 6.22 or lower) running with Windows then you may want to skip this next part and read ahead to where I discuss installing dual Windows.
Installing Real DOS with Windows:
To begin, I recommend that you format your C drive (having backed up your important files) to start afresh.
Then install DOS as normal followed by your CD-ROM driver.
Now that you have DOS and a working CD-ROM there are two ways to go. We could install Windows 3.x first or Windows 95 first. I will describe how to do this with Windows 95 first (because it's a little easier) and mention the other way later.
Now the trick to keeping your original version of DOS when installing Windows is to do a custom install. This simply brings up a few options while installing, nothing complicated and you can choose the defaults. This will leave the original DOS as it was. After it is fully installed you can press F8 when you see the words "Starting Windows 95" as you start up the computer. You will notice that there is an option there to start with your original version of DOS.
Installing Dual Windows:
To install Windows 3.x after installing Windows 95 you need to go into real DOS mode and install it using the custom install option. This will allow you to install to a different directory other than C:\windows. When asked you should install to a subdirectory on the C drive called C:\doors\windows or something.
After it is installed you can then start Windows 3.x by going into real DOS mode and then typing C:\doors\windows\win.com.
If for some reason you have already installed 3.x first and want to install Windows 95 then you need to copy the file c:\windows\win.com to a disk and then delete the file from the drive. Next install Windows 95 to a subdirectory and when it is completed copy the file win.com back to where it was. This prevents Windows 95 from detecting the previous version of Windows.
When you install real DOS and Windows 95 together you get two sets of autoexec.bat and config.sys files. While you are in Windows, the DOS files are renamed to autoexec.dos and config.dos but when you are in DOS mode the Windows files are renamed to autoexec.w40 and config.w40.
If you have to reinstall Windows over the top of itself to fix anything, always choose custom install or it will erase the real DOS version.
Have the BIOS virus detection disabled when installing Windows or Windows will hang while installing.
When you want to install a sound card in DOS you may get an error such as "Can only be installed under Windows" (this was the case for my Sound Blaster) so the trick is to install the sound card in Windows 3.x and it will also work in DOS even if delete Windows 3.x afterwards.