Been there, done that, have the T-shirt; owe him big time already, Paul.
Just ran into a small potential showstopper. The version of XP on the Fujitsu is MCE. Thurrot's walk-thru on slipstreaming says MCE owners are SOL. That was over 3 years ago, though, so maybe things have changed in the meantime.
Everyone can take a deep breath, haven't touched the machine yet - just sitting down in the chair in front of it raises the hair on the back of her neck... three rooms away.
As for when the problem started, it was sometime in the spring of 1970, but I digress.
The slowing of the computer & various annoyances have accumulated over the past 2-3 years but, as I've said, she is very change-averse & has discouraged messin' with it. What prompted my running sfc and then this post was a problem with iTunes not 'seeing' her iPhone when connected. It can see our iPod Mini, but iTunes won't/doesn't see her iPhone 3G, my iPhone 4 or my son's iPhone 4, even after updating iTunes to the latest version. It has successfully synced her phone a number of times before, but it's been awhile.