|"will a ATI X1300 256 ram pci video card play good video and world of war craft"|
You really should list your system specs. By "Intell 3 800", I assume you mean a Pentium 3 800MHz? Does the motherboard not have an AGP slot? The X1300 is a PCI-express card though there were some versions that were retrofitted to work with the older standard PCI bus. The PCI version is expensive (about $90) & would be a complete waste of money. Make sure you're shopping for the right kind of card...PCI & PCI-express are two completely different things & they do NOT use the same slot. An old P3 system will NOT have a PCI-express slot.
"Currently the desktop has a geforce 5600 fx 32 memory video card"
The FX5600 didn't come in a 32MB version. I believe it only came with 128MB or 256MB.