Why do you care? Because if you’re a UK internet user, sometimes you will want to click on the “show results from sites in the UK” button. And if you’re a chrome user, sometimes this button won’t be there because it keeps sending you to google.com by default.
Chrome is a bit precious on how it lets you handle the google.com search engine entry – it doesn’t let you edit the URL that it uses.
If you go to Tools -> Options -> Default Search -> Manage, then Edit the google (default) entry, you’ll see that it has a mysterious “{google:baseURL}”, where the domain name would normally be.
Furthermore, if you search your preferences files in your Chrome profile, you’ll notice that the definition of this {google:baseURL} is nowhere to be found.
Now, you might be thinking, “just set it to use the google UK search”, but if you do that then only search results from sites within the UK will be returned in a search, which probably isn’t what you want most of the time. You might also be thinking “create a new search entry and point it to the usual google.co.uk/search?q=%s”, but if you do that you lose google suggest.
So the trick really is to work out how to change what Chrome inserts where it sees “{google:baseURL}”.
The solution:
Turns out Chrome builds this from the google cookies that you have in your browser. All I did to fix this was to delete all cookies from google.com . I left my google.co.uk , gmail.com etc. alone. After restarting chrome, I am now getting all my searches through google.co.uk, and I can refine to just UK results with a single click again.

doesn’t work for me