I played some old Apple II games recently and applewin emulator works great in winxp under virtualbox for a while. (It is kind of funny and maybe partially ironic to run emulator under another virtual os.) However, the simulation window one day just disappeared. Even reinstalling the emulator doesn’t work, I could have restored to previous virtualbox state but unfortunately I didn’t kept a snapshot before that.
It turns out IE could have a similar problem and the fix is easy.
Simply open regedit and look for Window X-Position and Window Y-Position under
HKEY_CURRENT_USER\Software\AppleWin\CurrentVersion\Preferences\
They are probably set to some ridiculous value (I got something like 32768 for my X-Position). Just set them to some reasonable value (say 10) and restart, the window should reappear.