General scenario to be covered to test desktop application manually:
1. Functionality test as per specs of the application
2. Usability tests.
3. Screen load/ Operation times/ Response times.
4. Fail over scenarios, mostly depend on application
5. Compatibility testing.
6. Installation, then re-installation testing.
7. Recovery testing, what if application crashes. Is data lost?
8. Print functionality.
9. Keyboard shortcuts (Hot-keys).
10. Cut/ Copy/ Paste functionality.
11. Minimize/ Maximize/ Resize.
12. Help functionality.