It's possible to install Windows 95 on top of a MS-DOS partition, but you are limited to a 2GB partition size and FAT16 filesystem.

Install MS-DOS, Windows 3.x and after install Windows 95 in the same partition. When prompted that there is an existing Windows version, press OK and select a different folder for Windows 95 (C:\win95 for example).

After the installation, Windows 95 will boot by default. If you want to change to MS-DOS, press F8 when the message Starting Windows appears and select "Previous operating system" or something like that and you'll boot onto MS-DOS.

The boot loader renames the files *.DOS or *.WIN on root of C: depending on the OS you choose.

That's how I remember it, too.

Just make a backup of your DOS files (autoexec.bat, config.sys) and choose a different directory for Windows 95.
Say WIN95 or WINDOWS.95

If needed, you can re-insert the old drivers with a text-editor (if you use Win95 DOS instead of DOS 6.22).
Things like MSCDEX and the DOS CD-ROM driver are often removed by Windows 95 Setup.

Just add them back. Windows 95 will use them.
Technically, Windows 95 itself does not need MSCDEX anymore, also.
It has the CD extension built-in. So it's sufficient to load the CD-ROM driver alone.
For Windows 95, I mean. DOS and Windows still need both.
This practice was used in the early days of Windows 95,
when proprietary CD-ROM drives still existed,
but Windows 95 had no Windows drivers for it.

Just one note about Windows 3.1x ws Windows for Workgroups 3.11.

WfW uses VFAT, which is managed/implemented by a *.vxd.
It may not work properly on Win95 DOS which supports FAT32 and FAT16+LFN.

There's a patch for DOS 7 which makes things more compatible, though.
Just keep in mind that it's not possible to use a Windows 3.1 HDD driver (FastDisk) here.

Useless information. Please do not read:

Ok, technically, it's possible to make DOS 7 to use old hard disk utilities.
The LOCK command can help here.
It will allow DOS programs that aren't DOS 7 aware to fully access the HDD.

However, that's dangerous to do if the DOS installation exceeds the old world order.

The old limitations, I mean.
CHS maxium, DOS 3.x partition maximum (32 MB for old FAT16),
2GB partition maximum in DOS 4-6 etc.
Things like that.

Applies for things like PC-Tools before version ~v6 (say PC Tools v4).
Programs released in the DOS 4 era should be fine already.

Good luck! 🙂🤞

It should noted the initial RTM version (Start ME UP!! blah blah )of Windows 95 does not support FAT32. Only FAT16 is supported by the first public release of Windows 95..

Windows95 OSR 2.0(win 95B) up do support FAT32 file systems.

+1

Win95 will use long filenames on FAT16, however.
These may confuse the Virtual FAT driver of WfW 3.11.
Or rather, DOS 7.x won't allow the VFAT to mess with the FAT directly.

It could trigger that message about the "LOCK" command, not sure. It's been 20+ years since I dual-booted Win95/3.x.

Another issue might be the permanent swap file of Windows 3.1x.
It's needed for Win32s, I think.
The swapfile is contiguous (one piece) and can't be moved. It's a special file.
Creating it requires (maybe) direct access to the FAT, too.

benjibarnicals wrote on 2022-07-23, 18:06:

Hey all, […]
Show full quote

Hey all,

I have a 486 PC, 16mb ram with a DX4/75 (though clocked at 100) with Windows 3.11 and DOS6.22 installed on a 2gb CF card (running EZ-BIOS to overcome the size limitations). I'm thinking about getting Windows 95 installed and wondering if there is a "safe" and reliable way to dual boot my setup. Without destroying anything. If its worth doing at all.

Anyone had experience with this that may shed any light/guides/thoughts?

Ta,

Ben

When you mention Win 3.11 do you mean MS Windows 3.11 or MS Windows for Workgroups 3.11?

Ahhh thanks all. Interesting things to note to read, I hadn't considered about long file names.

Oh its Windows 3.11WfW that I have installed (MarkP).

I have a custom autoexec/config files at the moment for my current build so I can boot up DOS with various drivers/settings installed or into Windows 3x etc. So I def want to keep that, and perhaps build on it with other options. I'll keep a backup of them anyway.

Considering I'm running the machine with CF cards, maybe I should just use another CF card with a pure Windows 95 install and keep it simple 😁

I'm going to have a look and see what to do, I'm pretty sure I have another CF card laying around somewhere so I'll have a look.

Just as a side note, as its been a long time since I installed win95 before too. Does it require DOS6.22 to be installed first before installing Win95, or not needed at all (does Win95 install its own version of DOS - DOS 7?!), i'm just wondering if I install Win95 without DOS6.22 first and Win95 would then install its own version of DOS 7, if its still compatible with old DOS games like Monkey Island etc etc.

Thanks all!

benjibarnicals wrote on 2022-07-24, 08:20:

Ahhh thanks all. Interesting things to note to read, I hadn't considered about long file names. […]
Show full quote

Ahhh thanks all. Interesting things to note to read, I hadn't considered about long file names.

Oh its Windows 3.11WfW that I have installed (MarkP).

I have a custom autoexec/config files at the moment for my current build so I can boot up DOS with various drivers/settings installed or into Windows 3x etc. So I def want to keep that, and perhaps build on it with other options. I'll keep a backup of them anyway.

Considering I'm running the machine with CF cards, maybe I should just use another CF card with a pure Windows 95 install and keep it simple 😁

I'm going to have a look and see what to do, I'm pretty sure I have another CF card laying around somewhere so I'll have a look.

Just as a side note, as its been a long time since I installed win95 before too. Does it require DOS6.22 to be installed first before installing Win95, or not needed at all (does Win95 install its own version of DOS - DOS 7?!), i'm just wondering if I install Win95 without DOS6.22 first and Win95 would then install its own version of DOS 7, if its still compatible with old DOS games like Monkey Island etc etc.

Thanks all!

No Windows 95 comes with it own version of MS Dos Version 7 for the first version. Win95B and Win95C(OSR 2.0 and OSR 2.5) have M S Dos 7.1 and FAT 32 support. Both Win98 versions of MS Dos is 7.1 as well.