Can this system be upgraded to play todays games?

My brother wants to play AION, but his PC is really bad (atleast in my standards)
He wants to spend as little money as possible but have a good PC that wont lag to death in aion/wow..

My main question is- what could i put on this mobo to make the PC faster? I think it says it has a PCI slot but dont know any good older cards that would perform well?

This is the information he e-mailed me - i told him its all junk and its time to build new JUST WANNA MAKE SURE

1. Western Digital,160GB, SATA, WD1600JB-00REA0
Specifications:
Manufacture: Western Digital
Capacity: 160 GB
Interface: IDE
Rotation Speed: 7200
Cache: 8MB

2. BFG 512 MB DDR2 Nvidia 7300 GT
Specifications:
Core Clock - 350mhz
AGP

3. MOBO - Asus P4P800
Specifications:
Intel 865PE Chipset
800FSB
Dual DDR400

4. 3GB Kingston HyperX KHX3500

5. x86 Family 15 Model 2 Stepping 9 GenuineIntel~3079 MHz

what kind of cpu does he have? If it's a celeron i'd think you'd need to upgrade both the cpu and video card.

As far as the video card, I know i've seen ATI 4670's that are AGP... That could be a good bet for graphics. If the cpu is a p4 or pD, you might be able to just do that...

But if it's a celeron, i'd think it would need to be upgraded too.

I just looked up system requirements though and for recommmended it has p4 3.0, nvidia 6600...

Maybe he can buy the game first, see how it runs and if it runs like crap... upgrade!