Out in the technical communities I still see a lot of people telling people to use msconfig (Microsoft System Configuration Utility) to stop applications running on startup with Windows.
Now this was a fine tool - back in the old days (it first shipped with Windows 98), but it hasn't changed much since then and is geared towards technical users.
Windows Defender is often overlooked as being a simple anti-spyware application. But it has some great features which surpass a lot of the functionality that msconfig was often used for.
The Software Explorer is one of them, you can find it under Tools. It offers a few different options from the drop down menu, startup programs, which allows you to see and block any specific applications from starting with the system.
Although a common source of confusion for non-technical users is the 'Show for all users' button, which is required to make any system-wide changes (most applications set themselves to startup system-wide). So you often need to elevate using that button to make any changes, else the buttons are greyed out. I think that needs to be made more clear, or Defender needs to ask for elevation automatically upon starting the Software Explorer.
It also let's you see currently running programs, and also programs that are connected to the network (you previously had to go to the command line to check that), and also to which addresses they are connected.
What would I like to see done to Defender in future versions?
Consider moving the Software Explorer function out and having it as a standalone application, and put it under Programs in the Control Panel, although it does have a sub-option (View currently running programs) under Defender I think it is worthy of its own entry. Also put a shortcut in the System Tools folder in the Start Menu.
In addition I'd like to see Windows Defender move on to provide basic anti-virus. Windows Defender is already the best anti-spyware application out there in my opinion, it doesn't put icons in the tray, it doesn't launch loads of junk on startup and it doesn't pop up nagging you about things, with definition updates installed automatically over Windows Update is great.
This is really something where Microsoft are out in front of the pack (except with Windows Live Messenger), other software developers write software that tries to take over half your computer and load dozens of applications at startup slowing everything down, instead of getting out of the way and letting you get on with things. No doubt Microsoft would face an anti-trust investigation for bundling anti-virus with Windows (may be they could make it a downloadable plug-in), but it would be worth it for the end-user experience.
No doubt people will mention OneCare, but OneCare is a heavy all-in-one application suite, I don't see the point in having a firewall, anti-spyware etc when that stuff is already built into the system. Let OneCare be the heavy security suite, let Defender be the minimalistic simple low resource anti-malware application that it could be.