Z2 Xp Ahci Sata Raid

I need to use XP it's a requirement from the company I work at. I previously used Z13 (which was easy to install XP on) but now I have Z21

I'm following the instructions on the website however I don't have a USB CD and Floppy Drive so I'm using a bootable USB to install XP

I have slipstreamed the SATA Driver (which I downloaded from Sony's website after entering in my model number) into the bootable USB, however upon entering setup I get a BSOD with the following error
STOP: 0x0000007B (0xF78D2524,0xC0000034,0x00000000,0x00000000)

After googling for a bit I see this appears to be an AHCI error
However I was under the impression the SATA Driver I downloaded and slipstreamed into the bootable USB should prevent this, at least this worked on the Z13, however there I was using the CD drive and not a bootable USB.

What could have caused this error during setup? Does the slipstreamed driver not work when using a bootable USB? Should I use an external floppy USB drive for the SATA driver? Or is there possibly some AHCI settings in the bios? (Sony's website does not mention AHCI when installing XP, nor are there any AHCI options visible in the bios.) Any help would be greatly appreciated!

Thank you so much for your time. Please have a great day!

 

Please, does anyone know what's wrong?