DOSBox doesn’t automatically see your computer's hard drive for security reasons. You have to "mount" your QBasic folder as a virtual drive. Open .
If the window is tiny on a 4K monitor, open the dosbox.conf file and change the windowresolution setting to 1280x1024 or use the "overlay" output mode. how to download qbasic dosbox
If you'd like to dive deeper, I can show you how to so QBasic opens instantly, or I can provide some classic code snippets like "Nibbles" or "Gorilla.bas" to test your setup. Which would you prefer? how to download qbasic dosbox
Download the installer for Windows, macOS, or Linux. how to download qbasic dosbox