I recently had to reinstall XP, and on my previous system I had three hard drives: C:/ with XP and some programs; G:/ with games and programs; and W:/ with movies and miscellenia. I had to reformat because of a virus, and I went from XP Professional to XP Black (basically XP Professional with a bunch of themes to make it look like Vista). I installed it onto a 20GB IDE drive (very old - think Compaq persario), and it ran fine. I only ran that drive on the system for about a week or so (didn't need anything of importance off my other drives). I then hooked up the drive formerly known as G:/ (SATA 320GB, Western Digital). It was detected immediately, and I could access all of my data. Then earlier this week, I needed to get a movie from my W:/ drive (SATA 500GB, Hitachi). I switch the G:/ drive's power connector over to the W:/ drive (all the SATA connections are still there, just no power to the other drives). I boot up, the bubble pops up at the bottom of my screen initiating the install of the drive (did the same thing for my G:/ drive), and once it finishes, I go to My Computer to find that it's not there.
It shows up on my BIOS. Everything is on automatic detection. The drive is receiving power, for I can here it spin when the system starts. It does not show up in Disk Manager at all, though.
I'm going to check out the jumpers as soon as I finish this post.