That may be so, and if true, this is going to be a disaster. I imagine that there's a real chance of losing all my data (pix, music, ect.)
Then why would the drive work at all if formatting is needed? What you're saying is that with no format, there are no tracks laid down for the drive to organize itself. Why is it working at all?
The problem then is that Seagate's software lied. I followed the instructions. I was ready for a format to start with, I started it with the expectation that I'd just let the thing format overnight then get into the rest of it the next morning.
For a long time, I've been wondering how drive manufacturer's were going to handle the ever bigger drives with ever longer format times. If it took a bit over 4 hours for a 1 Tb, then formatting 1.5 Tb should be over 6 hours, and a 2 Tb close to 9. That's a lot of time. And will only get worse, much worse, as bigger and bigger drives are made and sold. Imagine a time when 10 Tb disks are built and sold. Wanna spend 45 hours formatting?
So, imagine my pleasure at Seagate's software simply getting down to business, partitioning and cloning my new drive in around 2.5 hours. FWIW, the PC I use is a Core 2 quad Q9300 2.5 Ghz. The original drive is a Seagate SATA 750 Gb. Which should still be bootable, but I've already gone onto it, uninstalled a few programs and deleted the whole Users directory. Oops.
While my procedure may be faulty, Seagate's instructions then are sorely lacking. This is nowhere near the first time i've setup a hard drive (more like the 20th), but it *IS* the first time I chose to use the drive manufacturer's software instead of following the long arduous OS process of partitioning/formatting/reinstalling all programs. Going the long way of course is very very time consuming, in fact, if I had chosen that route, I'd still be at it. Seagate's software offered a way around, quite frankly, a distasteful amount of format time.
So, since the instructions advised that I have my OS's install disk ready, but didn't ask for me to put it in the CD drive, that perhaps there's some Microsoft way of fixing what's wrong with the boot process.
Here's what the error looks like - the BIOS does it's thing, recognizes both drives at the correct capacity, then goes to a screen with the bar on the bottom with the green leds that trace from left to right. Then, when it should go the next screen with the big blue dot and the Microsoft flag in the middle of that dot, it instead reboots, does the BIOS again then pops up with a black screen and that message. At that point, if I tell it to go ahead and boot normally, this time it does so. But for how long? I'm gonna have to fix this one way or the other.
I was hoping someone here had already experienced this and had a solution. Seldom have I been on the "bleeding edge", usually someone else has been there, done that and got the t-shirt. 
Thanks for those URLs!
I'll read those and consider my own situation. Error or not, right now at least the cloned drive lets me in at the moment.
Yes, the old drive still boots, unfortunately my haste to delete files has resulted in destroying my own login on the old drive. 
Fortunately the other login works, albeit with no icons other than the wastebasket on the screen. That's what I get for being in a rush. I just didn't let the new one "prove" itself before making big important changes.
So, onto the always painful process of learning.
Also, I tried running SeaTools for Windows. The top three items, the SMART test and the two drive self tests don't run. They come back with a "not supported" error (or somesuch, I may be paraphrasing). That includes the other HD, which itself is a Seagate 750 Gb drive which is the one that came with the machine and has been working, and still works, just fine.
