Look at Options -> Interface -> Show icon in system tray. Is checked? If yes then look at system tray (^).

Thank you - sorry, I must have been blind :oops: .

...and perhaps check that task bar's settings. Don't let the icons get grouped or hidden (when inactive).

These "features" in Win7 ...

After minimizing ProgDVB window the program is not accessible anymore.
The program entry is removed from the task bar and therefore the window may not be restored. ProgDVB is removed from taskmanager application list too and therefore the window may be restored only by closing the process ...