Q: For the past few months, I have been unable to run Windows Update properly. When the problem began, the program would find and list the needed updates and appear to download them. But then, after reporting "initializing installation," it would report installation failed, without providing an error number.

After a couple of months of that — and a long and fruitless exchange with Microsoft — the program reported a needed update for Windows Update itself. For this update, exactly the same thing happened: apparently successful download but failed installation. As a result, I now cannot even get to a list of needed updates.

The behavior of the computer is normal in every other way. In particular, it downloads and installs normally updates to the Norton suite as well as to Ad-Aware and SpyBot. Any idea what might be wrong and what I might do about it?

— David Cox, Bellingham

A: It still seems updates are more art than science. There are a lot of things that can cause them not to work properly, including not having enough free disk space or having some driver or application running that conflicts with the update program.

Here are a few things you can try. First, run the update just after booting Windows and before you have launched any unnecessary applications. If this doesn't do the trick, try loading Windows in safe mode.

Also, it sounds like you're talking about both Windows updates and Office updates, since you seem to be trying to install multiple updates at once. When such an attempt fails, I've found that trying to install a single update at a time often allows the procedure to succeed. And sometimes installing updates in a different order may result in success.

Often the error message reported when an update installation fails may point you to the problem. Even if no error messages are reported, you may find clues to the problem in the update log files.

The specific name and location of the log file depends not only on your operating system but also on whether you're updating Windows itself or Microsoft Office. You can find details on these log files by searching the Knowledge Base on Microsoft's Web site for "update log files."

Q: I have a Pentium II PC with Windows XP Home Edition upgraded from Windows ME, upgraded from Windows 98, upgraded from Windows 95. I have a 20-gigabyte hard drive with four partitions: C:, D:, E: and F:.

I periodically get a message when I log on that I have very little space on my C: drive. I have gotten into the habit of checking the amount using Windows Explorer. The free space varies from as low as 87 megabytes up to 350 megabytes. Is this variation real? What can I do to correct the problem?

— David Mack

A: My guess is your system is set up to use C: drive for your Windows virtual memory. Virtual memory, also known as a swap file, is actually hard drive space. When Windows can't fit everything into RAM it will write data temporarily to the swap file.

Windows XP, unlike some earlier versions of Windows, doesn't need to reserve a set amount of space for virtual memory. Instead, it can adjust the swap file depending upon conditions. That would explain why the free space on your drive may vary considerably.

By the way, you can change the settings for your virtual memory by going to the Control Panel and selecting the System utility. In the utility that pops up, click on the Advanced tab then in the Performance section click on the Settings button. Again, select the Advanced tab and then the Change button in the virtual memory section.

Questions for Patrick Marshall may be sent by e-mail to pmarshall@seattletimes.com or pgmarshall@pgmarshall.net, or by mail at Q&A/Technology, The Seattle Times, P.O. Box 70, Seattle, WA 98111. More columns at www.seattletimes.com/columnists.

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