His PC was equipped with Windows 2000. It doesn't work with versions of iTunes later than 7.3.2.
Also, his PC had a dinky little 8GB disk, about 95% full.
So yesterday I stuck a spare 250GB disk in there instead, and installed XP -- and then went on to install iTunes 7.4.3.
Also AVG, Spybot S&D, AdAware, Firefox, MS Office, Acrobat Reader, Nero, ...