You can slipstream the contents of the XP install disk with any updates. But there may be additional steps to consider if the original XP disk is for an OEM machine. For instance, for a Dell, the site below was useful a couple of years ago, but I don't know if it will still apply to recent Dell machines;
The other way is more manual. Find and download the SP3 update file and copy it to a CD/DVD. Reinstall Windows using the XP disk you have, and then update to SP3 from that downloaded file;
However, I have just noticed a comment from Microsoft;
"To install Windows XP Service Pack 3 (SP3), either Windows XP Service Pack 1a (SP1a) or Windows XP Service Pack 2 (SP2) must already be installed."
So it looks like you need XP SP1a to be able to install SP3.
Google will help with more general advice about XP slipstreaming.
I hope that helps.
reinstall Windows XP when I have downloaded SP3 and the original CD istall disc was only SP1?
Dell Dimension 4600
80 Gigabytes HDD
512 Megabytes DDR ram