I apologize, but I am giving answers that should be productive if you take the time to read them carefully. Please go back and read starting at my first reply. I'm sure if you do that, you will understand what is happening.
You have mentioned TWO things. DOSBox and QBasic. From what I gather, you use DOSBox to Run QBasic on Windows. Meaning you are running DOSBox, which creates a virtual "old" machine that QBasic will run on.
To do that, just like before, you need TWO things. You need DOSBox and you need QBasic. When you start DOSBox, you must give that virtual machine a c drive. In the past you have apparently done that by "mounting" the folder c: \qBasic as the virtual machine C drive. Then, inside of that DOSBox virtual machine, when you go to the C drive, you are actually in c: QBasic. According to your screen shot, you no longer have that QBasic folder. Please understand that I have no way of knowing exactly what you had set up originally. You were running a configuratuon of two separate pieces of software -, you appear to be missing one of those now and you need to put it back. What you are missing is what you used to have under c:\qbasic - once you find that from your old computer and put it back, you will be fine.
Hopefully you find that answer to be "productive". I have explained it in the most extraordinary, yet simple way that I know how.