...Find the Knowledgebase Number, type it into Google, and you can then navigate to the offline installation file for each update.. It's fairly time consuming, but you can manually download each file, save it to disc and when ready, simply double click on the file to install the update..
For example, regarding the latest/March 2013 Internet Explorer 8 "cumulative update" for Windows XP, the KnowledgeBase number is "KB2809289" and typing it into Google comes up with the information at the link below:
Google Search for "KB2809289"
The first link in the search takes you directly to the technical bulletin information site for the update.
Choose the link for shortcut link "IT Professionals" in the article and you'll go to the actual technical bulletin where the downloads are located..
Scroll through the various downloads for your version of Windows and Internet Explorer, and clicking on the link for XP/IE8 takes you to the download site below:
Download the file to your desktop and double click on it to install it, assuming you don't have it installed already.. Since this is the latest version of the "Cumulative Updates" for IE, you don't have to download all the previous IE updates of this type..
To update all of the updates necessary after Service Pack 3 of XP, it will take a while, but they can be saved to a DVD, or some other type of removal media.. In my situation, because quite a few of our computers were offline, or had horribly slow connections, I performed these steps monthly to keep the machines up to date.. As such, I saved them all for later use if necessary.. It's less time consuming to save those file a little at a time than to do it all at once, but the procedure is the same.
Hope this helps.