Dual Boot PC - WIndows 7 & Windows XP Assistance

I have a new pc which has come with a hard drive with windows 7 on it. I have added another SATA drive to which I have installed Windows XP (I have purchased this). The problem I have is XP does not support AHCI hard drive controllers. Windows 7 uses AHCI and the XP installation uses IDE. This means the only way I can use one operating system rather than the other is to disconnect one of the hard drives!

The reason I want to duel boot the machine is I have alot of old hardware and software that will not work with win7 and the virtual win xp in win 7 will not suppport the hardware.

Would you please quote to advise and support me to install ahci drivers in xp.