- last post: 01.01.0001 12:00 AM PDT
Well, what you've already got would severely hinder a 7800GS.
Here are the best things to do [if you just want to upgrade and not buy a new pc]:
1. Video card. The 6600GT will suit your needs for Halo and other games. It can be found for close to $100 these days, but those prices are often at less reliable stores. Ne wegg has a big list of them. The cheapest is a silent solution and requires two slots. If you don't have two available slots, then a single-slot card would obviously be your only choice. You need to be sure which slot you have. AGP, PCI, or PCI-Express. You can find descriptions and comparisons online to help you distinguish. Otherwise, perhaps take it to a computer retailer or a techie.
-Side note- If you don't want to spend that much for a card, then a 5500 to 5900 series will do for Halo. It won't be max settings, but it will be decent and better than what you have.
2. RAM. To be sure, take your pc to a retailer like CompUSA or have someone who knows the tech look at it to see whether you use DDR1 or DDR2. It's important since they aren't interchangeable. The best thing to do [if you want a gig] would be to sell what you've got on eBay and just buy two 512MB sticks. That way, it's all uniform and the probability of conflicts between brands and memory sticks sizes is reduced.
This all requires roughly $160-$190. It's what will help your performance in Halo and may give you acceptable frame rates in other games.
[Edited on 5/2/2006]