3rd disk partition(HD) not showing up during OS install

Want to install XP Pro on 3rd Hard drive for dual boot (my wife hates Windows 7).

Have Windows 7 Ultimate with 2 hard drives (windows 7 on one of them). Installed 3rd hard drive and shows in windows explorer and disk management.

I load XP CD and restart computer, boot to CD, start installation, but the 3rd hard drive (disk partition) is not showing up to install XP Pro. The other two drives are there.

How can I make the third hard drive (partition) visible to install XP Pro?

Thanks for those replies! The 2nd HD is storage and I was going to use that same Dual Boot Installation with Windows 7 and XP tutorial until the 3rd HD was not showing up during the install of XP Pro.

I am not at home now so I will have to try looking at the BIOS later, but thanks. I was thinking about that, but if it's showing in "My Computer" and Disk Managment, seems like I should see it when installing XP Pro.

You running in AHCI mode? If so it is possible that some of the SATA ports aren't visible with a drive connected until the OS is loaded (mine is that way with 6 ports, 5 and 6 can only be seen when in AHCI mode once in Windows).

Thanks, it looks like my problem is in the bios setting. What scenario would you do? If I changed to IDE in the bios, wouldn't that effect my drives?

As 2 HD show in the Win XP install setup, make your XP HD 2nd & DATA HD 3rd.

Your suggesting drive letter change...hummm. This might work and I will give it a try, thanks!

I hope someone can help again. I am not that familiar with setting the SATA in the BIOS. This is what I did to try and have a dual boot system (Windows 7 & XP Pro). I unplugged one HD with W7 & and the other for storage only. I left the 3rd HD plugged up and installed XP pro. I shut the PC off and plugged in the SATA cables as before (had the master SATA cable in the 3rd HD). When I booted up, it the Boot mgr is missing. After a couple of restarts, Windows 7 booted up and the 3rd HD was showing in My Computer. I installed EasyBCD (1.7.2) in Windows 7 and tried to configure dual boot, but it wouldn't boot to XP, just W7. I uninstalled EasyBCD and W7 still boots up OK. I have attached my Mother Board layout and SATA settings. Can someone look at it and tell me what to do in the BIOS to have a dual boot system?