if you expect anyone to do anything about it, one would need a little more information than that.

1. What version of OS X are you using
2. What version of iPhoto are you using.
3. When did you last backup your iPhoto library
4. You do backup your computer, right?
5. What steps have you taken already
6. Exactly what happens when you launch iPhoto
7. Does iPhoto work correctly if you log in under another account on that machine?
If no other account, then create one for yourself and log into it.
8. With regard to #5, have you tried rebuilding the iPhoto Database (Library)

P