In DOSBOX ctrl+F9 key combination is used to close Dosbox application. if you run c++ in it you will not able to use this key combination to run C++ Program.
But you can solve this problem by following these simple steps,
1. Open DOSBOX.
2. Press ctrl+F1. it will open the keymapper interface of DOSBOX.
3. At Keymapper interface click on shutdown(in picture it is highlighted).
4.Now Click on Del. it will delete the ctrl+F9 shortcut key used for closing DOSBOX. and you can
frequently use this key to RUN Program in C++.
5. Now Save and Exit. Your DosBox is ready to run C++ without ctrl+F9 Problem.
But you can solve this problem by following these simple steps,
1. Open DOSBOX.
2. Press ctrl+F1. it will open the keymapper interface of DOSBOX.
3. At Keymapper interface click on shutdown(in picture it is highlighted).
4.Now Click on Del. it will delete the ctrl+F9 shortcut key used for closing DOSBOX. and you can
frequently use this key to RUN Program in C++.
5. Now Save and Exit. Your DosBox is ready to run C++ without ctrl+F9 Problem.