Under the recommended spec we only need 2GB of RAM, which is nice but still shooting yourself in the foot to be honest. Check them out.
Oddly it’s not mentioned but don’t forget that Aliens Vs Predator is one of the first ever games to release that natively supports the new flashy DirectX 11 - it doesn’t need some patch that comes much later to ‘activate’ it or anything.
Minimum Requirements
Windows 7/ XP/Vista
1 GB System RAM (XP)/ 2 GB System RAM (Vista)
3.2 GHz Intel Pentium 4/Athlon 64 3000+ or equivalent processor
DirectX 9.0c compliant video card with 128 MB RAM (NVIDIA 6600 or better, ATI X1600 or better)
Recommended Requirements
Windows 7/ XP/Vista
Intel Core 2 Duo E6400 or equivalent processor
2 GB System RAM
DirectX 9.0c compliant video card with 512 MB RAM (NVIDIA 8800 series, ATI HD2900 PRO or better)
Source: Big Download