Cant acces local disk (C:) or (D:)

Hello,
i don't know why at all, but when i go to....
1. start.
2. click on my computer.
3. click on "local disk (C:)" or (D:) (any one)
the "search" thing comes up instead. (I'm talking about when you click start and search with the little animal character thing.) why doesn't the real thing come up? i don't know why it did this, i just got on one day, and then it did that when i tried to access my local disk (C:) or (D:)