External HD not found after Update XP Crash

Hello,
Not sure if my problem is hardware or software based yet, so I've cross-posted on the Windows forum also.

I've got a 1TB USB 2.0 Western Digital external hard drive that I've been ripping my entire CD collection to (lots of time and effort involved). I've been ripping to my C:\ drive, and then transferring blocks of files to the external drive when I come close to running out of room on the internal drive.

Last weekend, I kept getting prompts that Windows wanted to restart in order to install an update. As I had dangerously little room left on my hard drive to accommodate the update, I clicked "restart later" and started to tranfer about 15gb of files to the external drive to free up internal drive space before going to bed, anticipating that I'd restart the computer to perform the update in the morning. When I awoke, I found the computer had frozen while trying to shut down. When I restarted, I found I had lost several drivers, amongst other issues. I also was only able to see the external drive ind Windows Explorer by it's letter designation only - but with no file information. In Disk Manager, I was initially able to see the drive, and I THINK it was listed as being in RAW format, instead of its originally formatted FAT32 single partition format. Same thing happened when I hooked up the drive to my office laptop. I could see it, but that was about it. After a few tries, I could no longer see the drive, either in Explorer or Disk Manager. I haven't been able to getting back to being able to see the drive. I've tried WD Lifeguard Diagnostics and GetDataBack with no luck. I still can't see a listing for the drive. I've tried directly plugging in to a wall receptacle, changing cables, etc, but nothing's changed.
I haven't tried Knoppix yet, which I've seen some recommendations for. I'm hoping somebody here can help me.
Thanks-
Walter