I have set google.com as my home page in Internet Explorer but this switches to google.co.uk automatically. Is there a cookie on my PC or is it my ISP? Nicolas Blaza
Many global companies redirect you to a local site, because they want to display local ads, and use bandwidth efficiently. This geolocation is usually based on the IP address provided by your ISP. Google then stores the default in a cookie. In theory, if you click the "Go to Google.com" link it should be "sticky" but often isn't. You could try closing all browsers and deleting the Google cookie or setting http://www.google.com/intl/en/ as your browser home page.
Backchat: How do they do that? In general, it's done by compiling a database of IP addresses, the companies that own those addresses, and then the locations where they are generally used (see the Geolocation FAQ). It's an inexact science. For examples, try www.ip2location.com and www.dnsstuff.com/tools/city.ch
