That's likely all the installed stuff you have accumulated over time with components set to run at startup - not the OS itself. Think programs like iTunes, Flash, Skype, Java, to name just a few common things people install which is guilty of this (annoyingly even Microsoft's own programs like Messenger can contribute to the problem too). All of them do stuff at startup, be it checking for updates or kicking off background services.
Have a look at Autoruns[1], which is a great SysInternals tool to show you what is set to run at startup, and lets you selectively disable them.
I hear you, but I have to say it's mostly stuff that Lenovo packed into the box for me. There was a little bit of the 3rd party programs; Adobe; Skype; but mostly not. See my reply here http://news.ycombinator.com/item?id=2978973
Have a look at Autoruns[1], which is a great SysInternals tool to show you what is set to run at startup, and lets you selectively disable them.
[1] http://technet.microsoft.com/en-us/sysinternals/bb963902.asp...