My two favorite free adware scanning programs,Spybot Search & Destroy andAd-aware, do a great job of cleaning out adware, cookies, and other junk left behind by advertising sites. (Adware is software that generates pop-ups and sometimes tracks your Web browsing.) But they can do much more: Both offer some rarely discussed features to help you block a multitude of annoyances, defend the privacy of your data, and speed up Web browsing. Here are some of my favorite advanced features you may never have tried.

Turn off Windows Messenger Service:

For some time, spammers have been using the Windows Messenger Service (an administrative feature not to be confused with instant messaging applications) to send little pop-up ads to computers running Windows XP or 2000. The Messenger Control plug-in for Ad-Aware allows you to disable this annoyance quickly. Go tothis Lavasoft News article, click the Download Now button at the bottom of the page, and open the download in order to install the plug-in (you need to install Ad-aware first). Next, open Ad-aware and click the Plug-ins tton, double-click Messenger Control Plug-in, then click OK in the dialog box that appears. In the Messenger Control Plug-in's dialog box, click the Disable Messenger button to turn off this service.

Find out whether your browser has been hijacked:

If you're getting pop-up ads even when your browser isn't running and your system seems extremely unstable, an advertiser may have hijacked your browser. (Go to "Sneaky Apps Attack" for more about this phenomenon.) To find out, run Spybot in Advanced Mode: Click Start, Programs, Spybot Search & Destroy, Spybot S & D (advanced mode). Click the Tools button in the left pane to open the advanced utilities. Check to see what's listed when you click the ActiveX and then the BHOs buttons: Those categories of browser plug-ins or applets are where the programs involved in many browser hijackings reside, hidden from view. Any item with a large red X next to it signifies that the program is known spyware, and you can run a full Spybot scan to get rid of it.

Pull the plug on ad sites:


Spybot can block your computer from contacting the servers run by ad companies. As a result you'll get fewer pop-up ads, and many of those you do get will be blank windows. This also makes it considerably less likely that an unscrupulous ad company could take over your browser. Your Web browsing will be quicker, too. Start Spybot in Advanced Mode, and click Tools, Hosts file in the left pane. At the top of the window, click the button labeled Add Spybot S&D Hosts list, and then be patient--it can take about 5 minutes for the program to complete this step.

Block adware from installing itself without your knowledge:
In three mouse clicks, you can keep virtually all adware from installing itself in Internet Explorer. Once you've done a full system scan with Spybot, click the Immunize button in the left pane. In the window that opens, click the Immunize button, then the Install button just underneath it, and select the check box labeled 'Lock Hosts file read-only as protection against hijackers.' Note: If you plan to use the preceding tip on blocking ad sites, make sure you've followed its steps first before using this one.

Andrew Brandt is a senior associate editor forPC World. You can e-mail him at[email protected]. Clickhere to read previously published Privacy Watch columns.