My real time scanning is off on mcafee program,every time i turn it on it turns off again?

i bought this total protection from mcafee,i find out today that my real time scanning is off,i tried to turn it on and its turning it off like 3 seconds later,i tried several times and still the same bull****,i tried running full scan,it says an error has occured,then it says my computer is at risk,geez....not even three days i have it and already a problem?