I originally posted a needless rant here, and decided in the interests of being constructive and not wanting to look like a ranty loon forever, to take down the post and instead write about how I addressed a recent frustration I had when troubleshooting my brother’s Macbook (much easier than editing my original, slightly inane, post). I’m a PC user so apologies if the following is unbelieavably obvious…

So the problem was: iTunes and Software update would not connect despite the fact the internet was otherwise working.

To fix the issue, change your location to the profile for your local wireless network instead of ‘automatic’.

It was incredibly simple but when I originally Googled whatever the exact error message was I couldn’t find an answer. So hoping this helps anyone who has experienced the same issue, and I’ll live with the embarrassment if the reason I needed help with this was that most Mac users find this as natural as uninstalling an application by dragging it to the recycle bin…

Thanks to Rich whose comment on my original rant was reasonable and helpful.