Is Windows Defender useful?

I've seen it do something...once.

Most forum members use Microsoft Security Essentials, which also functions in place of Defender and it is turned off by default

It is suggested that you use Security Essentials and Malwarebytes for good protection. Defender will be turned off.

smarteyeball said:

I've seen it do something...once.

Hey, only one more time that me.

Defender is pointless if you run MSE as it will be turned off anyway, but if your antivirus of choice is something else, there's no harm in letting Defender run in the background.

Windows defender is purely anti-spyware. Some AVs do not also protect against spyware, so in that sense it can be useful. If you have MSE, AVG, Norton, or a plain anti-spyware program, you can feel free to turn it off if you want to.

Also, I got some weird spyware on XP once that was removed with Windows Defender. Never heard of it really helping any one since.