There are many Window Hiding tools available on the internet that lets you hide all open windows with a hotkey but some don’t offer password protect feature to restrict the access. This is where UltraHide freeware application will be useful, this app lets you hide any window with a hotkey and also lets you password protect that hidden window so that anyone has to enter the earlier set password to unlock it.
Launch the app, set the password to unlock hidden windows, by default 123 is set as password if you don’t want to use the password leave the password field blank. Once password is set click “Hide UltraHide to the tray”.
Now click on any window you want to hide from your boss or relatives using the Alt+Ctrl +Spacebar, UltraHide hides that window into the system tray. To access it again double-click on its icon in the tray and enter the password.
Cons: This program doesn’t allows to set custom hotkey where user may feel Alt+Ctrl+Spacebar hotkeys too inconvenient to use.
UltraHide works on Windows XP/Vista/7.