Well here is the Error Log for the Saving Issue, sorry I didn't post it before 😐

------------------------------------------------------------------------------
StarGunner
System Configuration (C) Copyright 1996
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ
þ
þ CMDLINE = C:\STARGUN.EXE
þ STARGUN =
þ version = 1.1a
þ compiled = Apr 09 1997 @ 19:31:49
þ memory = 1528k : 4194300k (1569208, 1568292 max)
þ ULTRASND = 240,3,3,5,5
þ BLASTER = A220 I7 D1 H5 T6
þ COMSPEC = Z:\COMMAND.COM
þ dos = 5.0
þ vrs = 17025

ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ
Error Log.. If this file contains any data below this StarGunner
line then please forward this to the Stargunner Team. (C) Copyright 1996
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ
þ
Mission 4 Zone 1 Stage 1 Level 1
Time 219 AuxTime 219

SeqList 219 109

ÃÄÄ 0 Alien1a Signs [ 214| 18] 96, 102 - Scr Drn Ful OnS Vis Res
ÃÄÄ 0 Alien1a Signs [ 213| 19] 216, 70 - Scr Drn Ful OnS Vis Res
ÀÄÄ 0 Alien1a Signs [ 212| 20] 269, 70 - Scr Drn Ful OnS Vis Res
Nodes = 3
------------------------------

Anims

Nodes = 0
------------------------------

BulletsList

Nodes = 0
------------------------------

BulletsList

Nodes = 0
------------------------------

BulletsList

Nodes = 0
------------------------------
Can't open save file [2:star0000.sav].

Call Stack:
Save::save ssave.cpp
save_game save.cpp
check_keyboard_save keyboard.cpp
do_gameloop gameloop.cpp
do_mainloop2 stargun.cpp
do_mainloop stargun.cpp
do_main stargun.cpp
---------------------------------------------------------------------

BTW I am very thankful for all the help you guys have put towards
this extremely confusing issue 😀

again my question: do you have write acces to the folder of stargunner ?

Qbix wrote:

again my question: do you have write acces to the folder of stargunner ?

I'm afraid I don't know what that means, sorry.

On a lighter note, I found a way to fix my annoying non save issue.
Here's exactly what I did.

1. Downloaded Stargunner v1.1 Freeware.
2. Installed 1.0 - 1.1 Registered Patch
3. Went to SG's Setup.exe, chose sound settings etc.
4. Started up Stargunner (Without Dosbox) despite having no
sound and being super choppy,and made a save and quicksave file
in the game, then exited
5. Downloaded a Front End for Dosbox called D-Fend v2
6. Told D-Fend where my Dosbox folder was
7. Added Stargunner to the game list and set ALL the settings it asked
me to configure to the max each setting could handle.
8. Ran the game (through d-fend and dosbox)
9. loaded the file I created when I was running SG without Dosbox earlier
10. Tried quicksaving over file that was already there, and worked...

Siiiiiiiiiiiggghhhh... STttaaaaarrrguunnnnerrrrrrr...

Thank you for all the help everyone has provided, much appreciated 😀

PS: If you don't understand my instructions/gibrish above, please
msg me asap, I will do my best to help you.

As qbix said, there must have been something wrong with the file creation
process in that directory. Most likely that file was present, but hidden or
something so the game couldn't overwrite it.
If you/somebody else has a working way to reproduce this problem on
different pcs, please post details here.