>Hi everybody,
>
>I have a little hacker, who somehow made Date/Time/Language options regional settings unavailable. If I click on Date/Time, it opens a Window to adjust time. But if I click on other options, nothing happens. How can I make it work again?
>
>
>Thanks a lot in advance.

Because my Windows at Home is installed w/o any users or other security I can't be in much help, but check:
Control Panel->Administrative tools->Computer management->Local Users and Groups and see if there is something suspicious there.