shippensburg

i am using win xp and office 2003, when i try to open an existing document in word or excel using the 'look in' drop down box office doesnt respond anymore, however i can still use my pc fine. If I try to open an existing document but this time navigate using the my computer option it works fine and doesnt crash. does anyone know how to stop it from crashing when i choose to use the 'look in' drop down box?