In order to run FarCry 3 Blood Dragon properly, your PC MUST meet or exceed these minimum requirements:

Minimum System Requirements
Supported OS: Windows® XP (SP3) / Windows Vista® (SP2) / Windows® 7 (SP1) / Windows® 8
Processor: 2.66 GHz Intel® Core™2 Duo E6700 or 3.00 GHz AMD Athlon™ 64 X2 6000+
Memory: 2 GB
Video Card: 512 MB DirectX® 9.0c–compliant 
DirectX: 9
Sound Card: DirectX 9.0c–compliant
Hard Drive Space: 3 GB available space
Supported peripherals: Keyboard and Mouse (Optional Xbox 360 controller)

Recommend System Specifications
Supported OS: Windows® XP (SP3) / Windows Vista® (SP2) / Windows® 7 (SP1) / Windows® 8
Processor: 2.93 GHz Intel® Core™ i3-530 or 3.10 GHz AMD Phenom™ II X2 550 or better
Memory: 4 GB
Video Card: 1024 MB DirectX 11–compliant or higher 
DirectX: 9
Sound Card: DirectX 9.0c–compliant 5.1 surround sound
Hard Drive Space: 3 GB
Supported peripherals: Keyboard and Mouse (Optional Xbox 360 controller)

Supported Video Cards at Time of Release 
AMD Radeon™ HD 2400 / 3000 / 4000 / 5000 / 6000 / 7000 series
NVIDIA® GeForce® 8800 GT / 9 / 200 / 400 / 500 / 600 series

Note: Laptop versions of these cards may work but are NOT officially supported.