UPDATED
I'm Portuguese. So, I have my web browser language settings set up as "pt-PT; en-US". I always thought that meant that I want Portuguese (Portugal) content if available; otherwise I want English (U.S.) content.
With these settings, when I browse to http://msdn.microsoft.com I get the general U.S. English content and a nice section of Portuguese (Portugal) content (Announcements).
In some other places of the enormous microsoft.com I usually get Portuguese (Brasil) when no Portuguese (Portugal) content is available (like MSDN Magazine articles). I can live with that because I can always change some setting (even if it's in the URL) to get the content in English (U.S.).
But with Windows Live it's way different.
Let's start with Search. If I want to use Windows Live Search (http://search.live.com/) I get redirected to http://www.live.com/?searchonly=true&mkt=pt-BR which is very useful if I'm looking, say, for a washing machine (máquina de lavar). I get all those nice links for shops where to buy a washing machine but I can't get there because Windows Local Live can't get me driving directions to get across the Atlantic Ocean (Google Maps gives me driving directions with the caveat that I have to get wet).
If I do not want to get across the Atlantic Ocean, I still have a check box to choose "Only from the Portugal" (exact translation) or "Only in Portuguese (Brasil)". But if I want English (U.S.) I need to know the URL switch "mkt=en-US". Google, on the other hand, acknowledges the fact that I'm Portuguese (from Portugal) and always redirects me to Google Portugal and doesn't confuse me with a Brazilian user. Even if I go to Google Brasil I can choose to see it in my Portuguese or there's. In either cases, there's a distinction between language and location. I can search Portuguese content in either cases but I can choose content in Portugal or Brazil depending on the site. Also, in both sites, I have a link to go to the main international site.
I saw this nice search box in a blog and I thought it would look nice in my blog. I followed the Get my own Search Box! link and found out that "the page I was looking for was not found". Why? Because my main browser language is not "en-US", that's why.
Windows Live Writer beta 2 is out and I tried to get it but couldn't ("mkt=en-US" doesn't work there). The same thing with the Windows Live Messenger 8.5 beta. Fortunately, Scott give direct links before I had found out I needed to change my browser's main language.
Now I'm happily blogging with Windows Live Writer beta 2, but although I run an en-US version of Windows, I have my regional settings set to pt-PT and, to get spell checking for English I have to use this trick.
Sometimes it's not just about how good your are, it's also about how good you treat your users.