I recommend you to:
Use SiSoftware Sandra to do a burn-in test.
Update all the system and hardware drivers.
Install SP1(might help, then again it might cause more issues).
Install the latest in freeware:
adaware
daemon tools
power toys
etc...

Also you might want to teach him how to setup a remote assistance that way he doesn't have to ask you to come over to help when the poo hits the fan...

http://www.microsoft.com/windowsxp/p...st/default.asp

Further, you might also want to set the PC to autoupdate windows critical files and patches, install IE SP1, etc...

I would show him how to defrag, scan disk, checkdisk etc... You might even set them up to run automatically at certain intervals...

Other than that, he should be more than happy with his new machine and windows XP Home edition.
As always if you run into any trouble let us know.
BB