POADB

Click Start>Run - type services.msc.
Locate the SymWMI Service service and double-click on it to open the Properties dialog.
Click the Stop button.
In the Startup type dropdown select Disabled.
Click the Apply button and then the Ok button.

Then start HiJackThis & go to Config>Misc.Tools...> Delete an NT service...
In the popup box that appears, type in SymWSC & click the OK button.

Run a scan in HJT and fix the following item:

O23 - Service: SymWMI Service (SymWSC) - Symantec Corporation - C:\Program Files\Common Files\Symantec Shared\Security Center\SymWSC.exe

And then delete all the folders pertaining to Symantec, including this one:

C:\Program Files\Common Files\Symantec Shared\

Go into regedit again and delete this item:

HKEY_CLASSES_ROOT\CLSID\{147A976F-EEE1-4377-8EA7-4716E4CDD239}

Reboot your computer.

Are you experieincing any problems now?