I'm not sure,but usually you install the sata drivers before installing xp so the only way to fix it may be to format and reinstall,having said that it may be possible to reinstall the Motherboard drivers off your motherboard cd,and the sata driver may be on that and reinstall them,like i said I'm not sure if that would work or what the outcome would be to your system if you tried it.Usually you copy the sata drivers to a floppy to install them so I'm not sure if the cd option would work anyway.
I did find this but don't know if it would work,and i have not tried this myself,so i will leave the choice to you.
Insert the floppy disk with the "nvatabus.sys" file into the floppy drive. At the command prompt, type copy a:\nvatabus.sys c:\windows\system32\drivers and hit <ENTER>. Once file has been copied, type "EXIT" and hit <ENTER>. This will reboot your system. Remove floppy from system.
When the system restarts hit cancel when all devices are detected,then reinstall your driver kit
Like i said i cant vouch for this working so whether or not you try it is up to you.