Why my norton performance monitoring disabled and i cannot manage to enable it back

Norton Security | Norton Internet Security
1

I m using norton internet security 2012 all the while but since ystd my performance monitoring is disable....and when i go to the setting and change it....i cannot be change....the performance monitoring still disable....Anyone know how come could this happen?

2

Have your tried rebooting the machine?

3

yes i reboot it...but still the same