Had some trouble on a Sony VAIO VGN-Z41WD which has been upgraded to Windows 7 by performing a complete installation. After installing just about every driver and after installing the necessary components for WWAN for 3G access to the internet, the software just bails out with an error stating it can't find the device.
A closer look in device manager reveals no sighting of said adapter. At first, I thought the device to be broken until I started thinking a little further. The manual states that devices can be turned on and off via the VAIO Control Center, meaning that the device could be presented but not powered on (thus, not appearing in device manager).
Only after installing the following components, I could succesfully reactivate the WWAN adapter:
Leaving out any of these results in a partially working Control Center and Smart Network device toggler.
If the WWAN still does not work, ensure you have installed these: