Minimum:
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
Graphics: 512 MB DirectX® 9.0c–compliant
DirectX®: DirectX® 9.0c
Hard Drive: 3 GB HD space
Sound: DirectX 9.0c–compliant
Perpherals Support: Windows-compatible keyboard, mouse, optional controller
Requires a UPlay account.
Recommended:
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
Graphics: 1024 MB DirectX 11–complaint or higher
DirectX®: DirectX® 11
Hard Drive: 3 GB HD space
Sound: 5.1 surround sound
Perpherals Support: Windows-compatible keyboard, mouse, Xbox 360 Controller for Windows
Requires a UPlay account.
source: Steam