Again a VBScript problem.
Here is a working code
Set WshShell = WScript.CreateObject(\"WScript.Shell\")
WshShell.Run \"\"\"C:\\Program Files\\TrueCrypt\
.Run starts a console ('DOS Box') to execute some other process/program. You can control the display mode of that console (e.g. hide it by passing SW_HIDE == 0 as param 2), but what this other program does to your screen is up to this process. Programs meant to be executed silently (should) accept arguments like --headless or /nogui, or (should) provide a suitable IPC (e.g. COM) interface. So how to start other programs 'in the background' can't be answered in a 'one strategy for all' way. AFAIK, the players offer COM/OCX interfaces, and using these certainly beats Sendkeys voodoo. So google for "iTunes.Application vbscript" or "Wmplayer.OCX." to get some hints about how to use these COM objects.