a form intialization trouble

hi everybody

    i have launched Visual Studio 2008 pro on my laptop (Win Xp sp 3)
    I did it one month ago (i have been using it without any trouble)
    Today i tried to build a windows form and i have got the following
    error message :


    in the output windows:


    1---an exception type

    a system.nullreferenceexception have occurs in Interests.exe


    when i am building :

    2---invalidoperationexception not handle :

    look exception.innerexception : an error occurs when building the form
    The reference of the object is not defined to an object instance


    Any help will be appreciable
    Regards
    armand
    PS