Windows Update sounds like an excellent idea: Anytime Microsoft has a patch or other improvement for its ever-imperfect operating system, your computer lets you know, and even installs the fix for you. Privacy concerns raised by allowing Windows to make regular and unobtrusive phone calls home to Microsoft erupted into outrage, however, following the discovery that the updates included Windows Genuine Advantage, an antipiracy utility that many recipients deemed outright spyware.

But acquiring an unwanted watchdog isn't the only risk associated with Windows updates. I don't have room to cover all of the problems that the many patches and add-ons Microsoft has released for the OS might cause. These tips will give you the upper hand on updates, and help you out when a patch goes bad.

Disable auto installs

The best way to solve a Windows update problem is to prevent it from happening in the first place. If you are concerned about contaminating your system with Windows Genuine Advantage or some other questionable update, instruct Windows not to install anything automatically: First, open Control Panel, and in XP's Category View click Security Center and then Automatic Updates. If you're using a version of Windows prior to XP--or if you're using XP's Classic View--either double-click the Automatic Updates icon or select it from the Control Panel menu.

Choose the option labeled Notify me but don't automatically download or install them. That way, when you learn what updates Windows wants to install, you can read about them and check the latest opinions on the Internet before deciding whether they're worth the risk of installing. You can also ensure that your system won't reboot itself when you're not there, and, say, prevent your automated backup from running.

Update Microsoft apps

If you find Windows Update helpful, maybe you'd like a similar system for keeping Office and other Microsoft products up-to-date. If so, fire up Internet Explorer and surf over to Windows Update. If you see a "Get Microsoft Update today!" headline, click the Go button; otherwise click the Express link just below the Windows Update banner. Follow the instructions to install the necessary software. Microsoft Update uses the same automatic settings as Windows Update.

Muzzle WGA's notifier

If you've already installed the Windows Genuine Advantage update, and it thinks your version of Windows isn't authentic (whether correctly or not), you can at least prevent the program from annoying you further with its accusations. To put an end to WGA's warning pop-ups, right-click the Windows Genuine Advantage logo in the system tray (the part of the taskbar that includes the clock), and choose Change Notifications Settings. Select Don't Notify Me Again. Now save the settings, respond to the appropriate prompts, and restart your computer.

If you don't want your copy of Windows Genuine Advantage to contact Microsoft on its own, you may be able to adjust the permission settings of a third-party firewall such as ZoneAlarm to block WGA from making connections over the Net.

Fix broken updates

Sometimes a windows update tells you to patch your system, but things go awry. Other times you successfully install an update--but when you return, Windows informs you that you need to install the same update. Here's what to do.

Find the culprit: To identify the update that isn't working, revisit the Windows Update or Microsoft Update site. You can get there by choosing Start, All Programs,Windows Update (or Microsoft Update) or Start, Windows Update (or Microsoft Update). At the site, click Review your update history on the left. The browser will display a green check next to the updates that you've installed successfully, and a red X adjacent to those that you haven't. Problem updates will likely appear many times in this list.