Ever since Microsoft introduced its own antivirus and anti-malware solution, I think it's been getting a lot of unhappy pushback from security vendors like Symantec and McAfee. That's the only reason I can imagine that Microsoft isn't automatically including it - enabled! - on every new system that it powers. Instead, you have to download it, but it's a free download and it's pretty darn easy to install.

And as for the other anti-virus solutions, I'm sure that they're still good and they definitely offer capabilities that Security Essentials doesn't offer, but if you haven't cracked open the hood in Windows 7, there's a lot you're missing.

To start, there's a built-in spyware protection system called Windows Defender that you might be running, but according to Microsoft, Windows Security Essentials replaces it. Indeed, MS says:

"...if you are running Microsoft Security Essentials, you do not need to run Windows Defender. Microsoft Security Essentials is designed to disable Windows Defender in order to manage the PC's real-time protection, including anti-virus, rootkits, Trojans and spyware."

An earlier version of this article had tutorial information about Windows Defender but, well, that was daft. So it's gone. Just FYI if you're confused by the comments below.

The first step to getting Microsoft Security Essentials running on your system is download it from the Microsoft Web site. You can most easily do that by going here: Download Microsoft Security Essentials.

Before it downloads, of course, you have to approve it:

Let's do it! Click on "Yes".

Ready to go? Here's the installer...

Click "Next" a few times, well, maybe a half-dozen times. :-)

Eventually you'll get the program going and will need to start by updating the virus and malware definitions file:

When that's completed, you should have something like this, though likely the versions and dates will be more recent (I hope!) than what I have:

Confusingly, at this point Microsoft Security Essentials not only isn't running, but often cannot be enabled by click on the big "turn on" button:

What I found was that I clicked the button then got a time out error that it couldn't enable the program. What the heck?

Fortunately, a reboot revealed that it had indeed been enabled and was running and good to go:

That's it. Between Security Essentials and Windows Defender, you should be set and -- finally! -- free from having to pay a subscription fee for a third-party company virus definitions file. Tell your prof she's spot on with this particular recommendation!