start -> Settings -> Control Panel -> Regional and Language options -> tab languages -> details... -> add... ->
Choose Germany / German in both of the drop down lists and hit the OK button.
In the default input language drop down list you can now choose the German keyboard layout or display the language bar or press the appropriate shortcuts to chang the layout.
hope that helps
best regards,
tele
(O_o vor lauter englisches OS glatt die Input Sprache verstellt
)