Try here: http://www.sis.com/download/
IN the first window click "chipset drivers", then "IDE Driver", then the appropriate OS you are using.
Just for clarity, did you run CPU-Z on the machine you are having trouble with, or just on the hard drive from that machine in a different computer? From your previous statement, it sounds like you took the HDD out and put it in another computer. You must get the chipset information from the machine from which you are having trouble. If nothing else, if the problem machine will at least POST, there should be some chipset information on the POST screen. Or, if you are goign into it anyway to remove the HDD, snap a pic of the mobo if you have a digital cam and post it.