How to change the default applications pinned to the taskbar?

"If programming is an option, a solution might be to write a program that would run on the first user logon, and which will do the taskbar changes that you want.

For a .Net solution, see the article
Pin and Un-pin items to/from the Windows 7 taskbar
where a .cs file is attached that contains a class that can:

Figure out if a given executable is pinned to the taskbar
Un-pin it from the taskbar
Pin it back to the taskbar

The above article is based on another :
Pin Items to the Start Menu or Windows 7 Taskbar via Script
where a similar approach is described using vbs scripts."