Vista x64 SP1 wont load into windows

Hey not too sure if this is the right area to post this but I have been digging and digging with no avail so hopefully you guys can help.

A friend of mine has a new system that I told him the parts to buy and he had it put together and had Vista x64 installed on it. Let me give the specs first:

Mobo: Asus M3A78-T
CPU: AMD Phenom X4 9850BE
RAM: 8GB of Corsair XMS2 Dominator PC28500
GPU: 2 HD4870s in CF
HDD: 2 Seagate 500GB 7200.11
Case: Thermaltake Xaser VI

Now its a kick ass sytem and at 1920x1200 in TF2 with everything maxed on one card he gets 150FPS. But the main problem is Vista asked him to update to SP1 so he did. Now he is unable to boot as it is missing a file, the ahcix64s.sys. I am trying to see how to get that back in the system/drivers folder but have not had Vista crash on me nore have I had to work on anything like that yet. I am woundering if it could be a AMD related problem or not since I saw a guy with the same problem on a older SB600 mobo.

Anywho is there anyone who has Vista x64 and can tell me how to get this file back? He tried a System via the Installation CD but it gave him the Gray Screen of Death while booting to the disc and he was going to try it again but hasn't gotten back to me yet.

Any help would be appreciated a lot.

i cant seem to download the 32 bit fix it says i dont have the right privledges or something here i dunno why can someone e-mail it to me porterc76@ hotmail.com

dude i applied the Rg file 32 i did as u listed i restarted and guess what ....... still same stupid message can u tell me why it's still doi9ng it and how to fix it bro