This is the hotfix I'm after: http://support.microsoft.com/kb/981214
They say that they will send me an email with the password, but the email they send doesn't actually include a password! (but otherwise looks the same as their example).
Can I get this hotfix some other way?
Finally found out how to do this.
Apparently the hotfix website was written by someone who, erm, didn't quite know what they were doing. More details here.
The fix is to open the link in Internet Explorer, and open it in several tabs. One of them will work, eventually. This advice is still applicable.