In Windows 8.1 and previous versions, the taskbar and Start menu settings would appear under Taskbar and Start Menu Properties dialog. With Windows 10, Microsoft moved the Start menu settings to the new Settings app.
With Windows 10 anniversary update, released in July 2016, Microsoft moved taskbar settings to the Settings app. Starting with Windows 10 build insider preview build 14271, you can find all taskbar settings under the Settings app.
In short, you can now access all taskbar settings by navigating to the Settings app. Settings like lock the taskbar, auto-hide the taskbar, use small taskbar buttons, turn on or off desktop preview feature, taskbar location on the screen, and taskbar settings for multiple displays can be found under the Taskbar category of the Settings app.
Method 1 of 2
Open taskbar settings in Windows 10
NOTE: This method works only in Windows 10 14271 or above builds. Please check your Windows 10 build number if taskbar settings are not appearing under Settings.
Step 1: Open the Settings app by clicking the Settings icon on the Start menu or simultaneously pressing the Windows logo and I keys.
Step 2: In the Settings app, click the Personalization category and then click Taskbar to see all taskbar settings.
Method 2 of 2
Open taskbar settings from the desktop
Step 1: Right-click on the empty area of the taskbar and then click Properties to open the Taskbar settings page in the Settings app.
Our 13 ways to customize the Windows 10 taskbar guide might also be of interest to you.