Does it give the option to uninstall it?
Edit: Also found an article explaining the normal procedure for updating the hal dll, http://support.microsoft.com/kb/Q234558.
Beyond that I am out of ideas.
In Msconfig under the boot tab click advanced options, in this menu you should see a check box for "detect hal", check it than click ok and reboot. This worked for me when my system lost a core after updating to vista sp1.
Because it's a game they are interested in, games like it are the reason the PS2 was so popular and GameCube/XBOX were not. If MS can get a steady flow of these types of games in Japan than they have a very good chance of taking the console crown from Sony.
What about something like this- http://www.newegg.com/Product/Product.asp?Item=N82E16833124065 ? Wouldn't it do most of what the Killer NIC claims to do?
If your not dead set on multi channel than I would suggest the Onkyo R805Xt slim stereo receiver. http://www.accessories4less.com/cgi-bin/item/ONKR805XT
I would say it's about half the height of those cube PC cases, maybe even a bit smaller.