In order for you to play The Witcher: Enhanced Edition Director's Cut on Windows with minimal graphics settings, your computer must meet the following requirements
Supported OS:
Microsoft® Windows® /XP/Vista
DirectX Version:
DirectX 9.0c (included) or higher
Processor:
Intel Pentium 4 2.4 GHz or Athlon 64 +2800 (Intel Pentium 4 3.0 GHz or AMD Athlon 64 +3000 recommended). Athlon XP series, such as the Athlon XP +2400, is not supported
Graphics:
NVIDIA GeForce 6600 or ATI Radeon 9800 or better (NVIDIA GeForce 7800 GTX or ATI Radeon X1950 XT or better recommended)
Memory:
1 GB RAM (2 GB RAM recommended)
Sound:
DirectX version 9.0c-compatible sound card
Hard Drive:
15 GB Free