PCI card slot and buying a graphics card

[taladraco]

This is a bit complicated. I have a slightly older motherboard, and it still has a PCI card slot. But I need a graphics card (I play WoW) and there aren't any good PCI graphics cards. The only ones that I can find are PCIe. I have seen adapters that could resolve this issue, maybe, but I'm in no way a computer tech and I'm a little confused as to if and how that works.

It's a homebuilt computer that my brother did up for me. Currently, I have a riser in there, since the case design requires it. So I guess my question is three-fold.

Is there a PCI to PCIe riser (as in a riser that plugs into a PCI slot, but allows me the use of PCIe cards)?

How well does a PCI to PCIe adapter work with graphics cards?

Would it be better to just get a new motherboard with the right slots?

[Calum]

A PCIe to PCI riser card doesn't really exist to do what you want.  I've seen PCI to PCI-E x1 adapters, however these require modifying to work with graphics cards as they are typically PCI-E X16, and thus larger than an X1 slot.  I wouldn't recommend going down this route as additionally, the PCI interface will choke any semi modern graphics card due to its low bandwidth and outdated design.
The issue I see, is that it sounds like you have an oddball case if you need a riser card, so will a newer motherboard fit?  And, if your board is old enough to have no PCI-E slots, is the rest of your system up to spec to make a new graphics card worthwhile at all?

If you could give us a little more information about your computer, we can see what would be the best option for you.