Pinning items to the start menu and task bar in Windows 7 can be complicated if you’re trying to do it via group policy object (GPO). That’s because pinned items are stored in he registry under HKCU.
To learn about all the policy settings to customize the taskbar layout and configure the taskbar behaviors, see Taskbar policy settings. Here are some considerations before you start configuring the taskbar pinned applications:
This is a step-by-step guide on how to Pin a Program/Item to Taskbar via GPO. There is no direct Group Policy Preference setting to Pin Items to Taskbar. Here, I have explained two processes, Pin Program/Item to Taskbar in Local PC and Pin a Program/Item
You can "pin" it to the Start Menu with Group Policy by enabling the Add the Run command to the Start Menu Group Policy setting under User Configuration|Policies|Administrative Templates|Start Menu and Taskbar.
With Taskbar Hide, from Eusing software, you can hide program windows completely with a hot key, or minimize programs to the System Tray instead of keeping icons in your taskbar.
This will allow you to enable and disable the ability for specific or all users to pin a program to the taskbar, and allow or prevent pinned programs from being shown on the taskbar for all users in Windows 7. Pin to Taskbar and pinned programs is enable