I've had that problem from time to time. Someone mentioned that it doesn't do it if the WLAN card is plugged in.
I think sometimes when I start it up, it is going out and trying to build a playlist, including looking in my networked folders (which contain about 4000 mp3 files).
To get around this, you can create a shortcut to the file wm_start in the windows folder, and use this shortcut to launch WMP. It should start right up (and play the welcome video), just like it does when you go to
www.ppcvides.com