|Well, I certainly can't explain how Knoppix could see a hard drive that isn't configured in the BIOS. |
Concerning the BIOS configuring the drive did you check out the variables I mentioned? As mentioned many SATA II hard drives have a jumper on the drive to only allow SATA I speeds for compatibility purposes.
You state you had this drive installed in this computer before. Was it connected to the same SATA port? Speaking of SATA ports, not all SATA ports are the same. Some will default to an IDE compatibility mode so SATA drivers are not needed. This works but does sacrifice the added speed you might gain from running in SATA II mode. Other ports may only support storage drives and can't be booted from. Then there are RAID only SATA ports.
I still can't explain why a hard drive that is NOT configured in the BIOS could show in ANY OS. If you say it is happening I have to take you word for it.
One possibility is that the BIOS IS configuring the drive but there is no indication of that.
I suggest you try entering the BIOS and disable fast boot and any LOGOS. Save on exit. This should allow you to see what is being configured in the BIOS.
If you are using either a SATA mode (AHCI) or a RAID mode, the drive may show in the POST screens but not in WinXP due to no SATA controller drivers being installed.