Boot time protection setting is grayed out

I recently had an incident regarding 3 viruses found and quarantined which I posted on 1/29 or 1 /30.

 

Due to that, I wanted to experiment with changing the boot time protection setting and change it from normal to aggressive.

 

However I find that the slider is grayed out so I can't change it.  My version of NIS is 2011 v. 18.6.0.29 - my OS is Windows 7, 64 bit.  Recent full scans with NIS 2011 and Malwarebytes are clean.  BTW, that slider is the only setting that is grayed out - all other settings in every area are accessible to be changed.

 

Could someone help me to find out what I can do to fix this.  Is there a setting or option somewhere else that may have to be changed in order for the boot time slider to be active?  Any suggestions or advice would be much appreciated.  I've included a screen shot to show what I'm seeing.

 

Thank you.Boot Time Setting Grayed Out.jpg