Below are the steps to hide search and task view button as per Windows 10 build 9879.
1. Download the WinTHButtonHider.zip file from below link
In order to download the file, you need to register an account on the host website.
2. After downloading the file, unzip it.
3. Now run the below mentioned command in Run.exe and you're done.
To undo this change, follow the steps mentioned below:
1. Press Ctrl+Shift+Esc to run the task manager.
2. Look for WinTHButtonHider.exe in the task list.
3. End the progress and that is all!