BUY THE ORIGINAL.
After that, download patch 1.04.
EDIT: In case anyone asks why i just said this, it's simple, riped versions of FPSC are most likely to be just a simple ZIP (no installation), that way, when you try to install any update, he just doesn't find the location of FPSC (no reg. in the system).
If you really ahve the original version, then i'm sorry, but that qwestion is the 1ยบ thing that comes to my mind, so, all i can say is: try reinstalling FPSC.
My love is seperated in 2 parts, 1 of them is 3ds Max 7, the other; FPSC.