Medion Akoya E4355D (Aldi) or upgrade my Dell Dimension 8400

Lunabu

Hi,
I've put a similar post up on the thread about the PC Aldi are selling on 4th Feb 2010, however, my question is more specific:
The PC Aldi are selling has a NVDIA GeForce 6210 DirectX 10 Graphics card which doesn't appear to be all that great. I don't do much gaming, but would like to be able to play games like Wow including extensions, AoE 3, Alone in the Dark, Jade Empire and maybe some newer games as they come out.
Would this graphics card be up to it? I wouldn't fancy buying a new PC and then having to go and shell out for a new graphics card as well.
Or would it be cheaper to upgrade my existing Dell Dimension 8400 which runs Windows XP? I've already upgraded the RAM to 2GB but haven't changed anything else on it.
I myself know very little about hardware, but if anybody can explain what I would need (if upgrade of the Dell would be a viable solution), I might be able to get a friend to help me out with this.
Many thanks!

dogpile

Those Aldi PC's are very hard to come by, gold dust to some (or sawdust to those who are picky)...basically dont set your heart on getting one too much unless you're prepared to queue at unGodly hours