|I'm also in the UK and they all open fine (the second link being a tad weird).|
Are you using Hosts files? If you don't know what I mean, try this:
Go to C:\Windows\system32\drivers\etc
You should find a file there called Hosts (no extension). Temporarily rename it to xHosts which will disable it. Close IE then open it and see if this helps.
[If there is more than one Hosts file showing you need to show all file extensions to determine the one that is just plain Hosts].
Could microsoft have been put into Restricted Sites somehow?
In Internet Explorer you go to Tools > Internet Options > Security tab > Restricted Sites icon > Sites button. Scroll through the websites looking for microsoft.com. If you are using SpywareBlaster there might be too many to wade through (it's a tiny little box).
We all live on a ball.