...at the full SP3 download link below, you can either have the "original" version of XP, or SP1 or SP2 as a prerequisite before installing SP3, so all versions are supported.. But, according to THIS LINK, you must have SP1 or later. So far, I have installed it on a single SP1 machine (not 1a) and multiple SP2 computers but have not tried on an "original" version without any service packs..
In order to download the full installer file for SP3, please use the link below. It's the one I've got saved on a CD and have used on 50 + computers so far. It's a large file, about 316 MB so you'll need a broadband connection to make it worthwhile.
Hope this helps.
Running: XP Home w/ SP1
I've just reinstalled XP Home w/ SP1 on my computer.
1. Now I find conflicting information on updating to SP3. Please settle the issue for me: do I need to install SP1a, then SP2, then SP3, or just SP3?
2. Also, because I only have dialup Internet on this computer, I want to download the Service Pack(s) to a flashdrive on my friend's broadband computer and transfer it to my computer. At what site can I obtain the SP download without it automatically trying to install on my friend's computer?