This is probably inanely obvious but I have trouble saving and loading the game. I was feeling nostalgic so thought I might give the game a go - especially since I have old savegame files from yesteryears. The game runs fine but I keep getting the "Disk Error" message whenever I try saving the a game or loading it. I double-checked that the dir was correct D:\Wizard7 and the save files but keep getting the message. Help!

The correct path should be C:\, so delete Wizard7 and replace D with C.

I decided a while back to make my second HDD my 'gaming' storage so I've been installing games into drive D. What's interesting is that it keeps asking me to "Insert savegame disk into drive D:" and when I press "Continue" the Disk Error message comes up!

It doesn't matter where you installed the game (in my case it's E:), DOSBox mounts your Wizardry directory as C.
This is from dosboxWizardry7_single.conf (DOSBox configuration file):

[autoexec]
# Lines in this section will be run at startup.

@ECHO OFF
mount C ".."
c:
cd DSAVANT
cls
ds.exe
exit

Brilliant! That little 'autoexec' word brings back memory. Thank you for point it out. C drive and nought else :D
Thaks again triock!