In order for you to play Singularity on Windows with minimal graphics settings, your computer must meet the following requirements
OS *:
Windows® XP/Vista/Windows 7 (Does not support Windows 2000)
Processor (CPU):
Intel Dual Core 2.8 GHz or AMD Ahtlon 64 x2 Dual-Core 4800+ or better
Memory (RAM):
1GB for XP, 2GB for Vista/Win7
Graphics Card:
3D hardware accelerator card required - 100% DirectX® 9.0c-compliant 256 MB video card and drivers*
DirectX®:
DirectX® 9.0c (Included)
Hard Drive:
8GB of uncompressed hard disk space (plus 400 MB for the Windows® swap file and 12 KB free for saved games)
Sound:
100% DirectX® 9.0c-compliant true 16-bit sound card and drivers
Other Requirements:
A 100% Windows® XP/Vista/Windows 7-compatible computer system
Keyboard/Mouse:
100% Windows® XP/Vista/Windows 7-compatible mouse, keyboard and drivers
*Supported Chipsets for Windows® XP/Vista/Windows 7
  - All NVIDIA® GeForce® 8800 GT 256 MB RAM and better chipsets (excluding 9400 cards)
  - All ATI Radeon™ X1800 256 MB RAM and better (excludes X1800 GTO, HD2400, HD2600, and HD3450)
  - Motherboard integrated video chipsets not supported