Many thanks for all your input, in common with 70+% pc users that I know of ,who are of course not malware savvy, son wants and enjoys computer for playing internet games , music downloads and sports streaming etc etc. As per suggestions I have installed Avast, MBam Pro ,Adblock, WebRep etc & got him using Sandboxie for web stuff and nowadays virtually no problems.
I still wouldnt recommend MSE to any friend or family, but unfortunately it comes preinstalled on vast majority of resale, reconditioned and new pc,s and leads average joes to believe it gives them protection . MSE always finishes bottom of independent expert reviews and AV tests and Microsoft itself have conceded its only "basic" and issued recommendation for people to use alternative Av's . Enough said. thanks