I was recently getting very frustrated because I was constantly getting results from Google in French in both IE8 and Google Chrome due to having either a Windows installation in French or other similar French language preferences even when going into "Manage Search Providers", I couldn't find the option to obtain UK or US but mainly English based results!
This is what I found out that may help you too!
The solution if you want the results from Google that you type in the top right hand corner of IE8 to be in English, is to click on the link below and choose Google Search as your default search provider:
http://www.ieaddons.com/en/search-helpers/
When I went into Manage Search Providers and clicked on Find More Search Providers I was also getting an error page!