That's strange
I'm assuming you have a desktop and not a laptop, I know memory can be a problem in some laptops. Either that or perhaps you haven't enough space on your desktop. However that might not explain why your disc drive is empty.
Does autorun.exe do anything?
Does your pc have all of these requirements?
CPU Intel Pentium 4 2.4 GHz or AMD Athlon 64 2800+ processor 2.4 GHz dual-core
Memory 512 MB (768 MB for Vista) 1024 MB RAM (2048 MB for Vista)
Hard Drive Space 8 GB of free space
Graphics Hardware Nvidia GeForce 6600 or ATI Radeon 9800 Pro Nvidia GeForce 7800 or ATI Radeon X1800:[23]
Sound Hardware 100% DirectX 9.0c compliant card Sound Blaster X-Fi (Optimized for EAX ADVANCED HD 4.0/5.0 compatible cards)
Try this link here
Can You RUN It?
It will tell you if your pc is capable of running the game. Let me know how you get on