36 minutes and still scanning... I finally installed Windows Defender tonight. I did a quick scan first which took all of 1 minute and 16 seconds. Now I'm running the full scan and time is passing. Compared to other anti-spyware scanners I use on a regular basis, Windows Defender is downright slow. So far no spyware has been found, which is normal for my machine.
EmailBattles.com has a write up about Microsoft's security apps including Windows Defender, Windows Live Safety Center, Malicious Software Removal Tool, Windows OneCare Live, and Microsoft Client Protection. I've only used the Malicious Software Removal Tool and now Defender, so I can't comment on the other apps, but it's an interesting read.
Finally, after 44 minutes, Windows Defender is done scanning. It did detect and correctly identify one malicious file in a zip archive, a file that I saved from a spyware infestation.
PCMag.com reviewed Windows Defender and gave it 2 1/2 stars out of 5. The review is detailed and thorough but says detection of 6 commercial keyloggers was tested. Sorry, but testing against 6 commercial keyloggers tells me next to nothing about how the app performs at dealing with spyware and adware users encounter every day on the net. If I had a commercial keylogger on my machine, yes, I'd want to know about it, but not many users will ever have commercial keyloggers. What users need to know is how an anti-spyware program performs at detecting and removing the spyware and adware encountered in the wild. Tomorrow I'll download some real-world adware and spyware to test Windows Defender and report the results here.
Update March 6, 2006: Finally I did the test of Windows Defender Beta 2 against real spyware in the wild. See the outcome here.