The minimum system requirements for Just Cause 2 are as follows:


OPERATING SYSTEM:
Microsoft Windows Vista (Windows XP is unsupported)
DIRECTX:
Microsoft DirectX 10
CPU:
Dual-core CPU with SSE3 (Athlon 64 X2 4200 / Pentium D 3GHz)
RAM:
2GB system Memory
GRAPHICS:
DX10 compatible graphics card with 256 MB of memory
(Nvidia GeForce 8800 series/ ATI Radeon HD 2600 Pro)
SOUND:
100% DirectX 10 compatible sound card
DVD-ROM:
Quad-speed (4x) DVD-ROM drive
HARD DRIVE:
10GB of free drive space
INPUT DEVICES:
Keyboard and Mouse.

The recommended system requirements for Just Cause 2 are as follows:

OPERATING SYSTEM:
Microsoft Windows Vista SP1 or Windows 7
DIRECTX:
Microsoft DirectX 10.1
CPU:
Intel Core® 2 Duo 2.6 GHz or AMD Phenom X3 2.4GHz or equivalent
RAM:
3GB system Memory
GRAPHICS:
DX10 compatible graphics card with 512 MB of memory
(Nvidia GeForce GTS 250 series/ ATI Radeon HD 5750 series)
SOUND:
100% DirectX 10 compatible Dolby Digital 5.1 sound card
DVD-ROM:
8 Speed DVD-ROM drive
HARD DRIVE:
10GB of free drive space
INPUT DEVICES:
Keyboard and Mouse. (Microsoft Xbox360 controller supported)

CPUs supporting SSE3

Athlon 64 Revision E/F/G : 2005-2008 : SSE SSE2 SSE3
Phenom : 2007 – 2008 : SSE SSE2 SSE3 SSE4a (not SSE4. 1/4.2)
Phenom II : 2009 – : SSE SSE2 SSE3 SSE4a (not SSE4. 1/4.2)

Graphic Cards supported

ATI Radeon HD 2400, 2600, 2900GT
ATI Radeon HD 3450, 3650, 3850, 3870, 3870 X2, 3870 Crossfire
ATI Radeon HD 4800, 4850, 4850 Crossfire, 4870, 4870 X2
Nvidia GeForce 8400 GS, 8500 GT, 8600 GTS, 8800 GT, 8800 GTS, 8800 SLI
Nvidia GeForce 9600 GT, 9800 GT, 9800 GTX
Nvidia Geforce GTX 260, GTX 280, GTX 280 SLI