What I was referring to was creating a general hotfix file with all the hotfixes after SP1, which I can put to CD and then I'll be able to install using an XP CD streamlined with SP1, then use the other CD with QChain to install hotfixes that came out after SP1 (up to the date that the QChain CD was created of course).
That app is for checking a certain machine, and I don't have a spare install of XP, with SP1 and no other hotfixes, to use the tool on.
I guess if I knew the date of the last update/hotfix that SP1 included, I could look on windows updates for any after that date?