In Windows Defender beta 2, new antispyware definitions are automatic (if you so choose)--an improvement over the original beta 1 offered last year. Moreover, automatic updates are free, making this the only free antispyware app to make such an offer. Defender gives you three levels of scan: QuickScan, Full Scan, and Custom. All three scans dig deep into compressed files, ferreting out hidden malicious executables.
Tools included within Windows Defender beta 2 include Software Explorer, which provides a snapshot of apps in your Startup folder that are currently running, along with network-connected processes and Winsock service providers, with details about each listed item. This allows you to monitor real-time processes on your PC like never before.
A controversial feature in this beta is automatic removal. In the Tools section, if you select the box next to "Apply actions on detected items during scanning," Windows Defender will automatically remove those items without you giving further consent. Other antispyware vendors have faced lawsuits with definitions and automatic removal with spyware vendors arguing that the end user should specifically remove the item, not the antipsyware app. Microsoft says that by selecting this option, you are giving permission for Windows Defender to remove future detected spyware. We'll see if this option remains in the final release.
Testing for beta 2 was unavailable at the time of this writing. In testing performed by CNET Download.com, Windows AntiSpyware beta 1 ended in the middle of the pack for overall performance. A full system scan required only 6 minutes, 55 seconds and identified many of the big-name spyware programs. Each trace was assigned a threat level, making it easy to identify particularly malicious threats. Microsoft AntiSpyware beta 1 also offered thorough definitions for spyware found on our system (something that remains true in Windows Defender beta 2). However, Windows AntiSpyware beta 1 left traces behind on our test machine for BookedSpace, eXact SearchBar, and Search Exe.