Hello
I have had the same problems: Bluetooth option in Wireless Switch Utility VAIO disappeared, and Control Center do not started. I have solved they by restoring the system to a previous state with the Windows System Restore, as jvp comment.
In my case, I suspect a lot that the problem has been because I have installed "Microsoft .NET Compact Framework v2 SP2". I needed it to install the Windows Mobile 6 emulator.
I have a
Sony Vaio VGN-SZ4XN with Vista Bussines.
Paco.