Is there any way to install the drivers for the ACHI SATA mode after I've installed XP? You know, rather than slipstreaming them or something similar... I'm experiencing random crashes as well, just locks up every so often. I had to change the HDD to IDE to get the win xp installer to recognize the hard drive. It's been a real pain in the ass... I don't think I'll ever piss about with the OS'es on laptops again. <_< Especially with an OS not designed for said laptop (XP).
Technically there is a way, but I wouldn't recommend it. You are supposted to install those driver during installation of Windows. Windows XP requires that the drivers be on a floppy though, if you don't slipsteam the drivers on to the Windows XP iso. AHCI and RAID drivers are installed in the same matter by pressing F6 when prompted. Without this driver and hard drive will not be recoginized.
That being said, there is almost no reason to bother with AHCI versus IDE compatiblity mode. AHCI only offers hot-swapping and NCQ. Not all hard drives have NCQ support.