To add the policy to a Windows machine, do the following:
Tap on the Windows-key, type gpedit.msc, and hit the Enter-key. This starts the Group Policy Editor on the system.
Use the sidebar to go to User Configuration > Administrative Templates > Start Menu and Taskbar.
Locate Remove Notifications and Action Center there. If the list is not sorted alphabetically, click on the “setting” column title to do so. This makes it easier to find the policy.
Double-click on the policy.
Set it to enabled.
Restart the PC
Windows Registry
Tap on the Windows-key, type regedit.exe, and hit the Enter-key on the keyboard afterwards.
Confirm the UAC prompt that appears.
Go to HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\Explorer using the left sidebar menu. If Explorer does not exist, right-click on Windows and select New > Key, and name it Explorer.
Right-click on Explorer, and select New > Dword (32-bit) Value.
Name it DisableNotificationCenter.
Double-click the new entry afterwards, and set its value to 1.
Restart the PC.