In the action center (taskbar) there is a red flag. Message : No Antivirus Program, no Antispyware etc. detected.
Solution 1:
Download and install a gratis tool "WinFix"
http://www.thewindowsclub.com/category/downloads
In the system tool section select the second last option, restart and you can see no red flad anymore.
Solution 2: (from a Symantec's supervisor:
1. Click the Start button, and then click All Programs > Accessories > Run.
2. In the Run dialog box, type the following text:
regsvr32 /u WMIUTILS.DLL
3. Click OK.
4. Restart the computer.
5. Click the Start button, and then click All Programs > Accessories > Run.
6. In the Run dialog box, type the following text:
regsvr32 WMIUTILS.DLL
7. Click OK.
8. Restart the computer.
That's it
TEXMEX001