Solution:
You can either delete your options.cfg or you can open it in notepad and edit the width and height values in there (set the values to say, 800 and 600 or any other "normal" values like 640 and 480, 1024 and 768).

You can find those variables under the "[Graphics Options]" header.
You must edit it on the same line and always behind the |. Spaces (or whitespace) are important and shouldn't be introduced, nor spaces afterwards. Also, only digits are allowed, no letters.

You can find options.cfg in the same directory as STBC.exe