Keeping up to date with every patch and hotfix that Microsoft releases for its OSs and various Internet-connected and macro-enabled applications can be a full-time job. And if your systems are visible to other computers on the network or on the Internet, keeping your system secure is extremely important. But what can the average end user or power user do? You don't have time to keep up on everything related to security, and it probably isn't your job to do so—unless you're an IT professional who supports power users. And what about your home computers? How can you keep current with all the security problems that might compromise your computers—or your users' computers?

Microsoft has an answer in the form of the Microsoft Personal Security Advisor (MPSA), which you can download here. MPSA is a Web-based system tester that checks your system against a Microsoft XML document that defines a secure system, alerts you to problems, and recommends ways to fix the less-secure parts of your OS and applications. MPSA installs the MPSA control, then downloads the MSSecure XML File. (If this description sounds like what the HFNetChk tool does for Web servers, you're right; MPSA is a version of the same technology, specific to client-side computers.) MPSA runs tests against the local computer and keeps all information on the local machine; the tool reports nothing back to Microsoft.

The tests seem to presume that the computer is exposed to the Internet and not behind any sort of firewall. My office computer sits behind two firewalls (one on the machine and one on the corporate network). MPSA alerted me that the system had a share that was available to any user with an account on our local Active Directory (AD) domain. The machine is invisible from outside our network (and from any network segment I haven't authorized on the local firewall), but MPSA downgraded the security because of that open share.

I'm technically savvy enough to know that this setup isn't really a security problem, but a less-experienced user might not fully understand the MPSA report. So I don't recommend this tool for the novice user, but readers of this newsletter likely will understand the foibles that this applet produces. MPSA is a useful tool for identifying missing hotfixes on your systems and helping you find those hotfixes. Although Microsoft doesn't officially support the tool, I ran it successfully on Windows XP Release Candidate 2 (RC2) as well as Windows 2000 Professional.

Inet Guardian Lite, from the Australian firm Drakar Pty Ltd, is another online security tester. Inet Guardian Lite installs a Web control, asks you a few questions, and then analyzes your system; the tool works locally, sending nothing over the Internet. Inet Guardian Lite suffers from the same problem as MPSA: It thinks your computer is exposed to the Internet. The tool also lacks the hotfix information that Microsoft provides, but it does provide a good, general set of guidelines for keeping your system secure. Go ahead and run them both; you can't be too secure.