How do I change localization settings in Windows?
If you are using Windows XP
Click 'Control Panel'
Click 'Regional and language options'
Change both drop-down boxes to UK
1- Open regional and language options in the control panel.
2- On the language tab click on details then click on the add button.
3- Select English (UK) from the drop down menu then tick keyboard layout/IME checkbox.
4- Select UK extended from the drop down menu then click ok.
5- Under keyboard select us and click the remove button.
6- Click apply. You'll most probably get an error message; if so select US again then click remove then when you click apply. This time it will work. Then press ok.
For Vista go to Control Panel then clock, language and region, then change country or region then click the keyboards and languages tab, then click change keyboards, then add and select English, United Kingdom. Once you have done that select the US keyboard and click remove. If it gives you an error message don't worry it will remove it later. Make sure that English, UK is in the default drop down and then click apply and then OK out and you are done.
The links Hovsep points to will show you how to do this, but apart from that, make sure all your localization options are as you want them. Often, the "US keyboard" is just the tip of the iceberg, and there is the issue of language settings (UK spelling), date formatting etc. They are all contained in the "clock, language and region" part of the control panel so it should only take a minute to check.
How to change your keyboard layout
Add a keyboard layout