Is Flash penetration that high? Based on the few "Mum at home with laptop" type people I know they're very wary of installing anything onto their Windows XP ma

Is Flash penetration that high? Based on the few "Mum at home with laptop" type people I know they're very wary of installing anything onto their Windows XP machines and they don't know the latest Flash plugin is any different from all the other things hammering to be installed.