QuickHide

QuickHide is a small-sized and portable piece of software with a very simple mission: it immediately hides all windows, along with the quick launch and notification area buttons once you trigger a key on the keyboard.
Similarly it can bring them up again to put all elements in the original location. The app does not feature any kind of options or configuration settings. Instead, it applies the "what you see is what you get" principle.

Use hotkeys to hide/show all windows and icons

There are two keys designated for hiding and making everything visible again, namely Ctrl and Shift, respectively. Unfortunately, they cannot be changed, which is troublesome when attempting to carry on with normal activity on the computer, especially if you're a fan on keyboard shortcuts in general, since the Ctrl and Shift keys are part of most global hotkeys, and QuickHide overrides them.

View the app in Task Manager only

The good news is that the program is not visible anywhere on the screen. It does not create a shortcut on the desktop or in the system tray area. Its process may only be observed in Task Manager, from where it can be terminated as well. For those looking to become stealthy regarding their PC activity, QuickHide could be of service, but it's not that useful if you're accustomed to resorting to hotkeys for basic commands.

Performance results

CPU and RAM consumption is minimal, so the tool does not put a strain on the overall performance of the computer. It had a great response time and did not trigger Windows to hang, crash or pop up error messages.

Portability benefits

Since installation is not an issue, you can simply drop the program files in any part of the hard disk and directly run the executable file, as well as save QuickHide to a USB flash drive or similar storage unit, in order to run it on any PC with minimum effort and no previous installers. What's more, it does not modify Windows registry settings or create extra tools on the disk, leaving it clean after removal.