Windows Update works, but Microsoft Update is in a different language

Hello,

I have a fresh Install of a German Windows XP with SP2 slipstreamed.
After the install I start Windows Update from the Start Menu, and after the
first ActiveX Control is installed, I get to the page, where I can choose to
do a "Schnellsuche" (Express Search) and "Benutzerdefinierte Suche" (Custom
Search).

On the right, there is a link to upgrade to Microsoft Update to get Office
Updates as well.
However, when I follow the link, I get to the english version of Microsoft
Update.

I already checked the Knowledgebase and made sure, that the only language in
Internet Explorer is German. But still MS Update page is English.

How do I fix that?

Thank you in advance for tips...