I just received a notification of Service Pack 3 for Windows XP availability when I opened my PC. (automatic updates – have mine set to notify when updates are available)
Here a link to Release Notes which I recommend reading before installing the update. [more]
In the release notes it says:
If you have installed Windows Internet Explorer® 7 or a beta version of
Internet Explorer 8, and then install Windows XP SP3, you cannot uninstall
To avoid this, ensure Internet Explorer 7 or a beta version of Internet
Explorer 8 is not installed before installing Windows XP SP3.
If you have already encountered this issue, uninstall Windows XP SP3,
uninstall Internet Explorer, and then reinstall Windows XP SP3.
Looks clear enough but will see and update with additional information I can find.