If you want to reduce any window to the system tray, I can heartily recommend RBTray.
From their website:
RBTray is a small Windows program that runs in the background and allows almost any window to be minimized to the system tray by right clicking its minimize button.
You can put the program in your startup folder and it will always run in the background. To access your startup folder, type shell:startup into explorer.
if you want to minimize a window, you could hit alt-space and this will show a menu in which you can press a letter (depending on your language) to minimize the window.