There are several different ways to update Windows computers. Most people use Windows Updates. That doesn't work well in a corporate environment, especially if you need to make sure that the computers get updated. Another useful way to update your computers is to use Altiris Patch Management. There have been a few great articles on Patch Management lately:
You can also download the updates from Microsoft and install them using Deployment Console. I found a great piece of software that will download updates for you. Here is the link: Windows Updates Downloader.
This software lets you pick what updates are downloaded and where they are saved. Here are some screenshots.
Once you have downloaded the updates, you can integrate them into your Windows XP files.
You can also create a job in Deployment Console. If you create a "Distribute Software" job, it can look like this:
Click to view.
This handy tool makes downloading updates easy. Check it out.
wuauclt /detectnow