My XP starts up loading about a dozen apps like print, sound, McAfee. I want to know why some don't make it.?

After a install, I notice a diff set of apps not the full set. I have to reboot two three times to get them all back. They come up like clockwork allmost all the time. How is that? What's all the activity on the internet when I have nothing running. Who's requesting pages on the internet when no apps are running?