I understand about clicking 'Shut Down!' What I am asking is, after XP support ends and to avoid system vulnerability do you 'recommend' leaving the computer on or turning it off? If turning it off is 'safer, 'should all 3 modem connections still be left plugged in and will the computer still be 'connected' to the Internet by leaving the connections plugged in?
Does Firefox 28 have the orange, oblong button in the top left corner in order to toggle the text links on? When I press ALT, it just highlights the 'File' option.
By unchecking clearing cookies on exit in the submenu, I assume you mean 'Privacy, History, Settings' and uncheck 'Cookies' under History-It is not worded as 'clearing Cookies on exit' but as 'When I quit Firefox it should automatically clear-Cookies.'
Just shutdown the PC. Thst's all you need to do.
To see the view with the oblong, orange button, right click a blank part of the Tab bar and click "Menu" bar. You'll see then that there aren't any text links. If you hit ALT with that view, the text links will appear. Click "Menu bar" again to go back to the view you have now.
Click the "Help" button bottom right in each of the Options menus to see what the settings do. Much better that you get into the habit of helping yourself rather than relying on other people all the time.
If something's not working, or your machine is infected with a virus or something, we can help out with that, but for the rest, I'm sure you're quite capable to using a search engine to find the answers to what happens to your computer when you unplug the power cable.