The drive letters of the host OS don't really matter to the drive letters in DOSBox, and you ask for compatibility problems with games to use arbitrary drive letters. Many games will tolerate gaps in drive letter assignment, but some won't.

In general you should mount a C: drive as a hard disk, and a D: drive as a CD-ROM. For example:

mount c c:\dos
imgmount d cdimage.cue -t iso

Hmm. Not sure I completely understand.

> The drive letters of the host OS don't really matter to the drive letters in DOSBox

But in my case it will not work with anything except j.

Here is the complete way:

1. I create Games directory in C:\

2. I run this:

1mount c c:\games
2imgmount x "c:\users\john\downloads\this game\game.cue" -t iso
3x:
4setup.exe

3. Then, the game could be successfully installed and launched.

4. Then I close DOSBox and create the following dosbox.conf file in game dir:

1[cpu]
2cycles=20000
3
4[autoexec]
5imgmount j "c:\users\john\downloads\games\this game\game.cue" -t iso

And then I create the following shortcut:

1"c:\program files\dosbox-0.74-2\dosbox.exe" "c:\games\game\game.exe" -conf "c:\games\game\dosbox.conf" -exit -fullscreen

And then, the game will stop properly work if I change j in dosbox.conf to something different. It will ask me to insert CD.

Use these commands to install:

1mount c c:\games
2imgmount d "c:\users\john\downloads\this game\game.cue" -t iso
3d:
4setup.exe

Use these conf settings to run the installed game:

1[cpu]
2cycles=20000
3
4[autoexec]
5mount c c:\games
6imgmount d "c:\users\john\downloads\this game\game.cue" -t iso
7c:
8cd game
9game.exe

Use this shortcut to run the installed game:

1"c:\program files\dosbox-0.74-2\dosbox.exe" -conf "c:\games\game\dosbox.conf" -exit -fullscreen

Again, a C: drive as a hard disk, a D: drive as a CD-ROM, and keep the mounted drives the same for both installation and playing. Every cdrom-based DOS game ever made will work with this arrangement of drive letters. If it does not then you have made a mistake, your copy of the game is broken in some way, or DOSBox has an issue with the game in question that should probably be investigated.

Thank you very much. Indeed, it works correctly now.