How to disable window 10 upgrade notification (on windows 8.1)

Hi, I have genuine windows 8.1 and I don't want to upgrade to windows 10 unless its very important. It is working good and I am happy with it. But problem is that after recent windows upgrade, there is now notification taskbar asking me to upgrade to windows 10 for free but I don't want to do that. If I really need windows 10 then I will buy new machine. Clicking that windows icon in notification area brings a pop up telling me about benefit of windows 10 like below :

Attachment 2470

Any idea how to disable it or I just need to ignore it ?

It came through automatic windows update. Disabling is as easy uninstalling that very update:

You can disable it by following procedure:

1. Open Control Panel
2. Open "Windows Update"
3. Look for "Installed Updates" at lower left corner.
4. Now open it and search for "KB3035583" (through search bar in top right corner).
5. Now Uninstall it and reboot.

It is actually GWX.exe pushed by microsoft to encourage user for windows 10 install / upgrade.