No one but the pure in heart can find google.co.uk

• Or, for the benefit of the search engines, "How to change the default search engine in Firefox".

Have you ever known someone reasonably well, got on okay, even ventured beyond that into a rewarding friendship ... but every now and then you find a hangup in their lives that just defies all rational explanation?

Like convincing Firefox that you'd like it to use Google.co.uk as a search engine rather than Google.com. So easy, surely? And not likely to be a rare requirement: so, something Mozilla would have slipped in right up front. They are friendly and cuddly and not Microsoft so they love you and want to make your life easy in every way. Except that they don't and frankly they have no intention of doing so.

First, and most obvious, option - click on the little arrow in the search box that lists the search engines available, click on "Manage Search Engines" and change the Google URL. Except that you can't.

Okay ... why not, in an amusingly ironic Zen-type way, use Google to solve the problem? Enter a search term like "change default search engine in Firefox". And we're away.

The first option has an excitingly hack feel to it: it tells you to locate the file GOOGLE.XML in the folder C:\Program Files\Mozilla Firefox\searchplugins and change every instance of google.com to google.co.uk. Fine, easy, except that it doesn't work. Firefox still defaults to google.com.

Second option, and this one comes from Mozilla so it must be right! Type "about.config" in the URL bar, then type "keyword.url" in the filter box. Right click on the keyword.url option that appears below it and change the url in the pop-up box to google.co.uk. Fine, easy, doesn't work either.

Third option: go to http://mycroft.mozdev.org/search-engines.html. This is a page that lets you select a brand new search engine (which, for the purposes of this argument, Google UK is). You're presented with a variety of search boxes but hey, you're clever. You tell it to search for Google in the UK ... easy, right?

Well, no, because what pops up is every instance of a Google UK-based search page. Universities, companies ... they all use the thing. You don't want to make any of them the default search engine. But, go back to that search page and this time ignore the search boxes - click on "2. Google" in the list of popular domains below. Now you get a list of every country-specific Google page in the world and this time - right at the end, of course, since that's where U is in the alphabet, above only Uruguay, Venezuela and South Africa - you get the Holy Grail, Google UK. Do I want to install it? Yes! Oh, yes! Do I want to start using it right away? Hit me with it, baby!

If Galahad had used computers, he'd feel like I do now.