Does VoiceAttack still appear to be running, otherwise?
If the main window (with the profile dropdown and the log, I.E. the one that normally opens when VoiceAttack is started) is not visible, but but there is a taskbar entry or a system tray icon, try right-clicking either of those and using the "Relocate to Primary Display" option
If the main window is still visible, but the window to edit profiles is not, try using the "Reset Screens" button on the "System / Advanced" tab of the VoiceAttack options window and restarting VoiceAttack