The minimun requirements for the game are below and it looks like your machine is suitable
Minimum System Requirements
Operating System: Windows 2000/XP
Processor: Pentium 4 1.4 GHz or AMD Athlon equivalent
Memory: 512 MB RAM
Hard Disk Space: 2 GB Free
Video: DirectX 9.0c-compatible 64 MB video card with hardware pixel & vertex shaders
Sound: DirectX 7-compatible sound card or higher
DirectX: DirectX version 9.0c (included) or higher
The only thing I can think of is that maybe your hard disk is full of porn
and you don't have the required 2GB free space
There are gaming forums also so I would post to one of them for maybe better advice