I prefer to do complete instals, but remember that you most likely have a sata drive and xp cannot be installed on a sata drive without controllers, if the mini has a hidden partition with a recovery section back to factory settings that would be great and then you would only need to install the updates and any service packs that are needed, what was the initial service pack on the mine??
as long as either service pack 1 and/or service pack to are installed then you can go straight to service pack 3, and also is the mini a hewlett packard, because some hewlett packard models need to have a patch installed before installing service pack 3
I like to download and install
Portable Updates so I can get most of my updates installed offline BEFORE going to microsoft updates
you first install it (must be done on the machine you will be clean installing)
then you run search ONLINE, then download , to a flash drive. then after install run search OFFLINE, and install offline.
https://onedrive.live.com/?id=root&cid=D7389B68B3A275AD
above is my onedrive where I have sp3 and ie8 (from Microsoft) if you want to do them separately.
the sp3 from microsoft download center is for xp embedded and I would not want to install that, I do not know why they are not leaving the regular sp3 for IT in their catalog, but that is the one I have in my onedrive.
Just remember you will need to reinstall all your programs, an imaging will have all on the mini ready to replace, but that is the reason we are doing a clean install you do not want an image of a damaged system.
just copy any data from documents and have all your programs ready to reinstall, that means the foxpro also.