Yes, it is a HP OEM CD. Sorry if I didn't explain the problem properly, the "validation" I am referring to occurs when I try to boot from the XP Installation CD. I receive a message prompting me to insert the HP Restore CD for validation, after doing this (and provided the validation is successful) I am then prompted to re-insert the Installation CD to continue with setup. There is no Windows Installation on the laptop, the HDD is empty. If I try to install XP using the Installation CD, the SATA HDD is not recognised, which is why I need to slipstream the SATA drivers on to the Installation CD, but when I do that using nLite, I no longer get the message that I need to insert the HP Restore CD when I boot the laptop from the slipstreamed Installation CD. It appears that either nLite is amending the XP installation files or there is information on the original HP CD that is not being included in the slipstream process. You are correct, I did have a post about trying to install SATA drivers through floppy, but the outcome was that I couldn't do it without editing the Installation CD or getting hold of a new Installation CD. I am hoping I can use the Installation CD I currently have, but I don't know how to slipstream the SATA drivers on to a CD that is part of a 2-disk set?? Matthew