Hello Pascal,
Can you confirm that you are experiencing problems with the keyboard?
If this is a recent problem, you might consider using the system display option to restore (undo) Windows Recent changes:
http://windows.microsoft.com/nl-nl/windows-vista/what-is-system-restore
Additionally, you can also try using a different keyboard to see if it works normally.
If you have any other problems, please include specific details in your response and we will be happy to assist you.
Sincerely,
James