I came across this, looks like we shouldn't have many problems running GTA IV , pretty low recommended requirements I see!
I got the source from here
- OS: Windows XP SP2
- Processor: Dual core processor (Intel Pentium D or better)
- RAM: 2GB
- Hard Drive: 18GB free hard disk space
- Video Card: 512MB Direct3D 10 compatible video card or Direct3D 9 card compatible with Shader
- Drive: DVD-ROM dual-layer drive