Final Cut Wont Open

Alright, I installed Final Cut first then I installed motion, dvd pro ect. Now Final Cut wont open and apple says all I have to do is do a system update thing. I did do that and still it wont work. I have deleted all the files of Final Cut and Motion ect. But when I go to install Final Cut again it shows that Final Cut will take 0bits to install and it will be updated so I think that somewhere the program is already on the Hardrive somewhere. So does anyone know how I can fix this? Thank you.