In order for you to play Serious Sam HD: The Second Encounter on Windows with minimal graphics settings, your computer must meet the following requirements
OS *:
Windows XP w/SP1 or newer
Processor (CPU):
Intel Pentium 4 3+ Ghz or AMD Athlon64 3500+
Memory (RAM):
1 GB for Windows XP or 2 GB for Windows Vista
Hard Drive:
2.2 GB free space
Graphics Card:
nVidia GeForce 7600, ATI Radeon X1600 (Shader Model 3.0 Required)
Sound:
Direct X 9.0c compatible sound card
DirectX®:
DirectX 9.0c August 2009 Edition or newer