Halo Not Up to speed. Wifi not working either.

I have halo 2 and a dell 531 inspiron.
Its VERY SLOW and i was told there were speed tweaks you could do to a computer to make it faster so halo 2 could run fast. i have the MINIMUM requirements for this. the bare minimum. Basically i have 2 gb ram
and a pitiful Graphic card. 6150 N vidia Geforce. anyone know how to tweak the speed of this computer?

And also: I have a wifi adapter for my wii/ds/psp and i dont know how to set it up so i can use it. I have the instructions and they confused me i dont know if im supposed to bridge or something. if i bridge though it tells me it cannot find anything that it can connect to. I have dsl (LAC) and a Wifi adapter Usb. can anyone help with one or the other?

I don't think your graphics card is capable of running Halo 2 properly, even though its an old game its technically flawed and demands the same kind of requirements as quite a lot of games in the past year have. You can try putting the image quality down to minimum, but then it wouldn't be very enjoyable. You could also try downloading the latest Nvidia drivers from their website, if yours are not up to date that could be your problem. However I'm not sure any of them options will grant you much success, if you have PCI-E or AGP slots in your motherboard you can buy Nvidia 6800/7800/8800 cards that will run the game exceptionally well

As for the WIFI problem, I also have a connection that does not seem to work and I think this could be because it recieves data rather than sends it, maybe thats why yours does not work correctly??...

I smacked up the minimum cache of the graphics card. its up to 256 mb. its still slow. i dont know. my computer is a vista and i got the vista halo 2