http://technet.microsoft.com/en-us/sysinternals/bb963902.aspx

Introduction

This utility, which has the most comprehensive
knowledge of auto-starting locations of any startup monitor, shows you
what programs are configured to run during system bootup or login, and
shows you the entries in the order Windows processes them. These
programs include ones in your startup folder, Run, RunOnce, and other
Registry keys. You can configure Autoruns to show other
locations, including Explorer shell extensions, toolbars, browser
helper objects, Winlogon notifications, auto-start services, and much
more. Autoruns goes way beyond the MSConfig utility bundled with Windows Me and XP.

Autoruns‘ Hide Signed Microsoft Entries
option helps you to zoom in on third-party auto-starting images that
have been added to your system and it has support for looking at the
auto-starting images configured for other accounts configured on a
system. Also included in the download package is a command-line
equivalent that can output in CSV format, Autorunsc.

You’ll probably be surprised at how many executables are launched automatically!