Error 0x80070002 Keeping Troubleshooters from working?

Hello,

I have a Dell Inspirom 15R laptop. Out of the blue, when trying to run a troubleshooter, I got an error message: An unexpected error has occurred. The troubleshooting wizard cannot continue.

Package ID: Windows Diagnostics
Path: C:\Windows\diagnostics\system\networking
Error code: 0X80070002
Source: Engine
User: XXXX-pc-xQAAAA/
Context: Restricted

My OS is Windows 7 64 bit. I use Firefox 4.0,1, Intel Core i3 CPU 2.54 GHz. I deleted the Temp files associated with my recent Windows updates with no change. I have rolled back to earlier restore points twice and the problem was resolved for about an hour and randomly occurred again.

Can anyone help? I am trying to set up a wireless network and without being able to use the troubleshooters to diagnose various problems that come up, I am dead in the water.

Thanks for any help you can give with this error code?
Thanks so much.