Until you install the SATA Drivers for your Hardware and XP.
To do this press the [b]F6 Key[/b] when the very first Blue Screen of the Windows Installer Appears and wait till prompted and Insert a Floppy with the SATA Drivers copied to it's Root into the A Drive and press Enter. This will load the SATA Driver and allow XP to access the HDD.
If you do not have a Floppy drive you will need to make a Slipstreamed Install Disc with the SATA Drivers Included. You can do this by reading the article here
http://articles.techrepublic.com.com/5100-10878_11-6150784.html?tag=rbxccnbtr1
Download the PDF version of this Article from here
http://downloads.techrepublic.com.com/abstract.aspx?docid=172974
While neither of these directly addresses the additional of SATA Drivers they do address adding Patches which is the same as adding the SATA Drivers.
Of you can use an application like nLite to include the SATA Drivers and anything else that takes your fancy in the way of Patches, Service Packs or Drivers. You should include any Realtech Sound Drivers at this stage if you are going to the trouble of making a Slipstreamed install Disc.
http://www.nliteos.com/download.html
If you use nLite make sure to read the Guides on their Web Site here
http://www.nliteos.com/guides.html
But before removing Vista open the Device Manager make a full list of all the Installed Hardware and see if you can find XP Drivers for all of it. If you can not find XP Drivers for any item this will not work under XP and you will not have a fully functional computer.
Col