To stop users from pinning to unpinning apps to the taskbar, you are able to remove the pin to taskbar option around the taskbar. Here the precise steps to follow.

One of the best reasons for the taskbar is it allows you to pin your most-used apps to the taskbar itself. To achieve that, all you need to do is right-click around the app icon and choose the "Pin to Taskbar" option. Once you choose the option, the app is going to be pinned towards the taskbar. Generally, the ability to pin or unpin apps in the taskbar is really useful. Actually, most users meticulously configure their taskbar to meet daily requirements. After configuring the taskbar as needed, you will possibly not want other users or yourself to pinning additional applications or unpinning the already pinned apps.

To create that happen, you are able to remove the pin to taskbar option and unpin from taskbar from the taskbar's right-click menu. Once you do that, no user can pin or unpin newly discovered apps around the taskbar.

Without further ado, let me show the steps to simply take away the pin to taskbar option from the taskbar's jumplist menu.

Edit Group policy to Remove Pin to Taskbar

You are able to disable taskbar pinning or unpinning from the Group Policy Editor itself. All you have to do is configure just one policy and you are done.

First, open the Run window. Just press the "Win + R" to open it.
Type "gpedit.msc" in the blank field.
Click "Ok" to open the audience Policy Editor.
After opening the neighborhood Group Policy Editor, visit the "User Configuration → Administrative Templates → Start Menu and Taskbar" folder.
On the right page, double-click around the "Do not allow pinning programs towards the Taskbar" policy.
After opening the insurance policy, choose the "Enabled" option.
Click "Apply".
Click "Ok".
Close the audience Policy Editor.
Restart Windows 10.

After restarting, users can no longer pin or unpin icons from the taskbar. i.e, the above policy successfully removed the Pin to taskbar and Unpin from Taskbar options in the right-click menu.

To revert back, set the insurance policy properties to "Not configured".

Registry Key to Remove Pin to Taskbar

You have to produce the "NoPinningToTaskbar" value in the Registry to get rid of the pin to taskbar option. This method is useful whenever you do not have access towards the local group policy editor.

Open the Run dialog box with "Win + R" keybinding.
In the Run window, type "regedit" and press Enter.
After opening the registry editor, paste the below path in the address bar and press and press Enter.
HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows
Right-click on the "Windows" folder.
Select "New → Key".
Name the folder as "Explorer".
Right-click on the "Explorer" folder.
Choose the "New → DWORD (32-bit) Value" option.
Name the new value as "NoPinningToTaskbar".
After creating the value, double-click on it.
Type "1" within the Value Data field.
Click "Ok".
Close the Registry Editor.
Restart the Windows 10 computer.

That is all. After restarting the system, you will no longer see the Pin to Taskbar option around the taskbar icon right-click options. Along with that, Unpin from taskbar choice is also removed.

To revert the alterations and show pin to taskbar, delete the "NoPinningToTaskbar" value.