Post how you mount the drives and start the game

Here's my usual approach:
mount c h:\dosgames
c:
cd kq5
sierra.exe

The game is fully installed to h:\dosgames\kq5 and does not need a CD in the drive.

When you click "Change directory", what is the value it shows as the current directory?

The problem is that you are not running the game the way the installer sets it up to be run. Normally there is a SIERRA folder with batch files to run the games in their subfolders beneath. The original batch file to run the game specifies the full path to the resource.cfg file (not relative path), and the game needs this path to know what the "default" directory for savegames is.

In your case, it should work if you run the game like "sierra c:\kq5\resource.cfg"

You need to exactly specify the path to the RESOURCE.CFG file when starting the game, i.e.

1mount c h:\dosgames
2c: 
3cd kq5 
4SIERRA.EXE C:\KQ5\RESOURCE.CFG

Thanks, that works. Every other Sierra DOS game works just fine when I just type "sierra.exe" or "sierra.com" or sometimes "scidhuv.exe," so I just took it for granted it would work on KQ5 too.

KQ5 is the only one that seems to display this behavior. Most DOS versions of the SCI games can be started without specifying the config file, as long as it is in the same directory as the game's executable. The Windows versions always need to have the config file path specified. The SCI games will write the savegame files to the same folder where the config file is.