The following are EA's requirement guidelines for PC versions of Tiberium Wars.
Windows XP, Windows Vista (32-bit; 64-bit versions of Vista are not supported)
2.0GHz or high, or AMD equivalent, Vista - 2.2 GHZ
512 MB or more, Vista - 1GB RAM or more
8x or faster DVD drive for retail SKUs, not required for digitally downloaded version
6.0 GB or more of free space
GeForce4, ATI Radeon 8500 or greater (ATI Radeon 9200 and 9250 PCI, NVIDIA Geforce 4 MX cards not supported.). Windows Vista - NVIDIA GeForce 6100 or ATI Radeon 9500 or greater. Labtop versions of these chipsets may work but are not supported.
DirectX 9.0c compatible sound card
Network, Internet Multiplayer:
2 players (no voice support) – 56 Kbps Internet connection
2-8 players (with voice transmission) – Broadband-class connection