TrayEverything is a lightweight portable application that minimizes
windows to the system tray even when the program lacks native support
for being parked in the tray.
In addition to simply minimizing windows to the tray, TrayEverything
also has options to add a button to the title bar of windows for
minimizing to the tray, hot keys to minimize, and even using
inactivity as a trigger to send a window to the tray.
If you'd like to keep a program running but don't need to tend to it
or would like to make sure nobody messes with it, TrayEverything can
minimize it without a visible icon in the tray and even
password-protect it.
For more system tray goodness, check out Trayconizer a program
that starts your program in the system tray from the moment it's run.
TrayEverything is a free download for Windows only.
Freeware application Trayconizer turns any application into a system
tray application in just a few steps.
Unlike other previously mentioned minimize-to-system-tray apps like
TrayIt or 4t Tray Minimizer, Trayconizer starts applications in the
system tray from the moment you run them.
To use it, you need to tweak the shortcut you're using to launch the
application (right-click shortcut and select Properties) by adding the
path to Trayconizer in front of the app like so:
C:\Path\To\Trayconizer.exe C:\Windows\Notepad.exe.
Trayconizer is freeware, Windows only, requires no install, and
consumes a paltry 2MB of RAM.
With Windows 10, you have the ability to create virtual desktops. The programs running on these desktops will not show up at all on other desktops. You could open the window on a separate desktop and switch back when you need it.
How to find virtual desktops:
Create a new desktop:
To switch desktops, just hit Task View again and your desktops will be at the bottom of your screen with a preview of that desktop for you to choose between.
Best Answer
I want to move icons from taskbar to system tray in Windows 7
Option 1: Tray Everything (free):
Source TrayEverything Stashes Programs in the System Tray
Option 2: Trayconizer (free):
Source Trayconizer Makes Any Program a Permanent System Tray App
Disclaimer
I am not affiliated with Tray Everything or Trayconizer in any way, I am just an end user of the software.