Wanna know a funny storey? My old computer was exactly one of those.
Hmmm, borderline stuff...
I'm going to assume you are running XP (1, because that computer seems real old
and 2 because XP was massively popular). You would need to upgrade the RAM for starters.
Upgrading the RAM is simple, but if you get the wrong kind, you could get in strife. I upgraded mine with 2x1GB DDR. Bad news is, thats the max the system can handle...
You'll also need to upgrade the GPU (which you don't have one currently). These are also known as "Video Cards". Now, I dropped a Powercolour HD3650 in mine. If your system is exactly the same as mine, you need an AGP video card, NOT A PCI-Express card. How do I know, I bought a PCI card and then it didn't fit
So, some suggestions:
G.SKILL Value 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400
Mushkin Enhanced Essentials 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400
Patriot Signature 2GB (2 x 1GB) 184-Pin DDR SDRAM DDR 400
All these are around the $60 mark. All three are good brands. I used the patriot brand in my last upgrade and i've used it again in my current build. Its good enough for what I need it for, that being, not much
GPU: (after not being able to find anything on newegg, I've had to resort to fleabay
PowerColor Radeon HD4670 1024MB 128-bit DDR AGP8x
And here's the bad news: $150!!!!! Which so isn't worth it...
My advice would be to save up and buy a new computer. These machines are seriously outdated.... Any money you spend upgrading this machine now is money down the drain because any components you use here won't be compatible with more advanced systems, should you buy new in the future. The AGP pinset is being phased out in exchange for PCI-express. RAM is up to DDR3@2600mhz (yours is DDR@400mhz). Also, there is no guarentee your machine will play those games well. Even after upgrading my machine, some games still lagged or took ages to load and it made things annoying.
If you were going to buy new, what would your budget be? We can give some suggestions that will let you play those games without having to worry about lag or anything.