Autoruns is a free Sysinternals tool from Microsoft that enumerates all the programs that automatically start on a Windows machine. You can then examine this list of programs to see if they should be running or should be disabled. Disabling unnecessary startups allows your computer to run more efficiently by reducing CPU usage and memory consumption.
When using Autoruns you will be presented with a list of all the executables on your computer that are starting automatically. This includes Windows services, Run entries, and many other less commonly known auto-start methods. When you research startup entries, BleepingComputer recommends that you first search within our Startup Database to see if they are known malware or programs that are not required to automatically start. Using this information you can then determine if the autostart should be disabled.
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!