I have approximately the same issue. I have tried to install XP professional (32-bit) in a dualboot config next to Vista 64-bit, which came with my PC. My PC is an HP Pavilion Elite m9350.be (for Belgium). It's a Core 2 Quad Q9300 2.5 Ghz machine and it has, as far as I know, one 750 GB SATA 3G disk, the INtel g33 express chipset, 4Gb DDR2 SDRAM. the motherboard is an ASUS IPIBL-LB, name HP/Compaq Benicia-GL8E. In the BIOS, the HD is set to RAID. I can perfectly install XP with the BOIS set to IDE. The only other option I have then, is to either enable or disable the second SATA controller. I leave it enabled. XP will only boot with the BIOS set to IDE, and Vista will only boot with RAID. I have tried to install the drivers automatically (unpacking, then installing the INF file), which doesn't work, and I've also tried to use the floppy method with F6 (USB drive), where I could select the driver. Then XP starts copying files, and when it wants to copy the Iastor.sys file and the three others it needs, it tells me they can't be installed. Maybe this is because I didn't ask it to install the chipset driver? I have no idea. I'm not really into this either (have learned a lot over the past week though), but now I want to try with nlite, which is basically the only option I have left. I have read through the forum, the guides, the faq... and I have already downloaded everything I need on a small external drive (Lacie LittleDisk). I am going to try to slipstream SP3, the Intel chipset and the SATA drivers. I presume I'm going to have trouble with the SATA drivers if I don't slipstream SP3. Anyway, if this works, I will become religious again, and you'll by my God. Let's see tonight... I will get started in about two hours. If anyone reads this and has some important pointers... I'll check back before I start. I'm new at this, but eager to learn! If you'll excuse me now, I have some praying to do.