Difference between Wndows Security Essentials and Windows Defender

Recently, I installed Avasti and uninstalled Windows Security Essentials because didn't need two antivirus programs. Then, Windows Defender "kicked in" and every couple of days it is updated with a ~35MB file. Why is the file so large when compared to the WSE updates?

Today, this file KB915597 (Definition 1.213.1225.0 the same version and also about ~34MB), was downloaded and installed twice. Once at 2:16pm and once at 7:39pm. Can someone please clue me in about what is going on???

Hi:

There is no such thing as "Windows Security Essentials".

For Windows 7 ONLY:

"Microsoft Security Essentials" is a free, Microsoft anti-virus -- it must be installed on its own. It is probably as good as any other free, anti-virus, although it has both fans and detractors.

"Windows Defender" is a weak anti-spyware application that comes pre-installed with Windows 7. Most folks probably agree that there are better, 3rd-party anti-malware/anti-spyware applications. It is not sufficient on its own -- you still need a robust, real-time anti-virus (either MSE or another, 3rd-party anti-virus).

I hope this helps a bit,

MM

Just to add...

Most 3rd-party AVs will automatically disable Windows Defender during their installation.
Some security suites with a firewall will also disable the Windows Firewall.

If that doesn't happen completely or correctly, then Windows Defender could still try to update its definitions/software in the background.
If that's the case, you can go into the Windows control panel to fully disable it.

Thanks,

MoxieMomma, Thank you!!!

Didn't realize that I can disable it. However, I read somewhere that now it's the same as Microsoft Security Essentials. Just curious.

ineuw said:

MoxieMomma, Thank you!!!

Didn't realize that I can disable it.

Yes, you can.

How to Turn Windows Defender On or Off in Windows 7

However, I read somewhere that now it's the same as Microsoft Security Essentials. Just curious.

That is only for Win 8/8.1/10.

They changed the name of MSE to WD and made it the built-in AV for those versions of Windows.

That's why I specifically mentioned in my first reply that it applied only to Win7.

It's confusing...

For Win7, there is no built-in AV. There is only WD, an anti-spyware. MSE is a standalone AV.

For Win 8/8.1/10, the built in AV is called WD, but it's just a rebranded version of MSE.

Clear as mud??

MM

To add to the confusion they both use the MsMpEng.exe

Thanks to all and now understand the relationship between Windows defender and MSE. As for turning it off, it done, and the Action Center indicates that Avasti is up and running. Thanks again.