I am trying to install XP in a separate partion of my new computer because some of my programs don't function with Vista. Since the new PC has no floppy, I repeated the process with nLite several times. After copying my original XP CD slipstreaming the SATA driver I get a blue screen before the installation starts. After copying the original XP CD adding SP2 and the SATA drivers I get a blue screen before the installation starts. Copying the original XP CD adding SP3 and the SATA driver works well until the XP installation stops at the moment it asks for the production key. I checked with nLite and the number is exactly the same (it's the very same number that was also in my old computer), but it says that it's invalid even before the number appears, and the installation refuses to proceed with any other number or without it. I've been trying to solve this problem for weeks already. What can I do to fix it?