Alright well...as the specs linked are a 450 mhz k6 anthalon and your system has maxium ram of 256, I would VERY strongly recomment you think about a newer system. Your current system when maxed out appears to meet one criteria of the MINIMUM system requirements for GuildWars. Everyone is budget conscious and I imagine you are too by asking about upgrades in a post. So if you are computer capable and not worried about trying to build a machine that will last for the next 5 years then I suggest maybe going
to this link here. It is a geek kit. That geek kit appears to support
a 1.8 ghz duron cpu they are selling also.
Please understand this isn't the best system obviously, likely all clearance and refurbished items and you gotta put it together yourself, but it's around $150(US) for everything and you can use some things from your current system such as the monitor and your current hard drive (I'd get a new hard drive and transfer your files you wanna keep to it as newer ones have better buffers and much faster access.). Maybe a friend can help you with it if your not all that computer savvy. Also consider whatever cash you might have laid out to purchase some upgrade card(s) for your current system will be much better spent on a newer system with more current slots and technologies.
Now if you got more than that to spend try looking at the geek auction area and searching the web for clearance machines. You might find a nice 2-2.6+ghz system for around 300.
. So i need help!
.