It's worth upgrading I'd say (others may disagree)
Does it have a videocard or is it integrated graphics?
If it does not have a video card, check if it has an AGP slot, or even a PCI-Express slot
You're going to want to get a new video card, along with the RAM
(We'll talk about videocards later once we know if you have AGP or PCI-Express)
The processor isn't that bad for being 4 years old
As for the RAM, you're going to need to look inside (or find the documentation) to see if there is an open slot for your new RAM stick. If there's only two RAM slots, and there are two sticks of 256 mb of RAM in each one, then you will have to take one out. But if, for example, there's two slots, and one stick of 512 mb, then your all set.
Make sure the RAM you're buying is the right kind for your motherboard too...
Here's a video from my band's last show Check out more (bigger) videos here http://www.youtube.com/user/icemanout
