Selecting Shutdown from Start brings up a drop-sown menu of options. Hitherto the default option has been Standby (which suits me) but, after downloading some Security updates from Microsoft another line in the menu has been created "Install updates and Shut Down" and it is to this line that the default pointer rests. Whereas before I could simply click without looking and get Standby, I now have to refrain from that automatic action and move to the Standby line in the menu. That's what I mean about "default"; the menu line selected when I initiate Shtdown.