In short, NO, not really or easily.

You can download SP3 from M$ Web Site, of course, you need to be AUTHENTIC. 

You can't inject SP3 into the original XP Image, unless you are adding it in as a FOLDER, and want to install it manually, and you need software to do that too.  IF that's the case, then you can install it separately when XP is done installing.  You can't make it part of the automated install package, DURING installation unless you know how to modify the install script to do so, and it's still work on your part.

IF you have a valid KEY, the installs with SP3 are, umm "available" for you elsewhere.   You can use the key needed ton install it, then CHANGE the key to his original key for validity.   

The way M$ used to be, a license is a license, version is irrelevant.  SO, no matter what version of XP Home you may have, the license is supposed to be valid.   IT is different now, with XP PRO, and XP PRO CORP.  Note, that with most versions of XP Pro you "acquire", you don't need to activate it once installed.   I acquired Vista Ultimate, and it's valid, activated, and updates.  I have Vista HOME on disc with a valid license too.  I also have a valid key for XP Home...

You will need a genuine copy to DOWNLOAD SP3, unless you can get SP3 in a newer install package of XP, which they ARE out there....

jcrt2000 wrote:

program you are looking for is nlite. and yes they have sp3 included on there add on page.

http://www.nliteos.com/download.html  That?  I don't see SP3 there anywhere.

So I can or can't inject it into the image? Could I inject SP2?

it's pain in the a$$ to get started with nlite (had to do one for my laptop) but once you get it, it works like a charm.

SP2 must be integrated before SP3 just so you don't go making any mistakes.