Team Fortress 2 System Requirements

MINIMUM:
OS: Windows® 7 (32/64-bit)/Vista/XP
Processor: 1.7 GHz Processor or better
Memory: 512 MB RAM
DirectX: Version 8.1
Network: Broadband Internet connection
Storage: 15 GB available space
Additional Notes: Mouse, Keyboard

RECOMMENDED:
OS: Windows® 7 (32/64-bit)
Processor: Pentium 4 processor (3.0GHz, or better)
Memory: 1 GB RAM
DirectX: Version 9.0c
Network: Broadband Internet connection
Storage: 15 GB available space
Additional Notes: Mouse, Keyboard

Where to get this game? Go to Steam Store!
Click here for Mac OS X requirements