Hmmm, I got this screen now.
"
Boot Manager Windows failed to start. A recent hardware or software change might be the cause. to fix the problem:
1. Insert your Windows installation disc and restart your computer.
2. Choose your language settings, and then click "Next."
3. "Repair your computer." ...
File: \Windows\system32\winload.exe
Status: 0xc000000e
Info: The selected entry could not be loaded because the application is missing or corrupt.
"
I have the options to continue or escape
Wow. We can't win. Do another BCD Edit from BING and let us know what is happening.
Escape from your screen.
When you ran msconfig, were there 2 boot entries? Which did you delete?
I don't want to jinks it but I think this time we succeeded. 
the little Windows logo is now on the drive and its now about 10 min after startup and Windows is not showing any device driver installations.
Buy the way the BCD editing of the Menu entries showed HD1 as HD unknown after I made it to be HD1 the first time. The Boot entries however stayed the same as before at {boot}
I'm slightly scared to restart after all this but when I think it should be finally OK .
Sounds good. Do a few restarts to make sure. Then we'll deal with the big HD.
Edit... In BING, is Win7 on HD0 or HD1?
I'm sorry it was HD0 for sure. And I'm also doing this with Vista installation not Win7.
By the way, if there are no more problems, I don't actually need the data on the big HD. The whole point was to move the Vista installation on the smaller hard drive and clear the bigger one for clean Windows 7 installation on RAID.
But for the sake of learning I think it is a good idea to try to fix the big HD too if you don't mind. I can't describe how grateful I am for your help.
HD0 is good.
I'm obviously a bit confused. Vista/Win7. Anyway you shouldn't have those two HDs connected together while the old OS is still on the big HD.
For the exercise you mentioned, disconnect the 250 GB HD and connect the 1 TB HD as HD0. Do what we've been discussing today. Same process. Clear Sig etc.
It should be easy this time.
Out of interest, are you planning on having Vista and Win7 in the same computer. If so I suggest using BING as the boot manager and avoid the Microsoft boot manager like the plague. BING keeps the OS independent, one isn't dependent on the other for booting files and you can remove either without affecting the other.
Edit.... I note one of your HDs is A: drive. I've never seen that before. A: drive has always been reserved for floppy drives. I guess you don't have a floppy drive.
Yes, I'm planning to do that for the time being. I will use mainly Windows 7 but Vista only occasionally.
Vista is now on a smaller IDE hard drive while Windows 7 will be on a SATA RAID volume.
I'm happy to hear that BING can do better boot management because I already made my mind to purchase it and have it all the time. I really like how it helped. I didn't even know that there was program to do such things. I will check the manual how to boot with BING, hopefully it is easy to understand. If not I may bother you again.
Thanks a million Brian.
And many thanks to all others for the helping hands. Very much appreciated
Unfortunately, BING isn't easy to use initially. It is overwhelming if you don't have help. Once you catch on it is easy.
Start a thread in Tech Outpost when you are ready to use BING. Let me know by PM in case I miss it. In the meantime there are some good BING tutorials here.
Thanks for the BING tips, I'll keep that in mind.
Oh, about the letter A, no I don't have a floppy drive, I just picked it form the list of available letters Windows gave me. It felt strange that I can use the letter A because I've never had and seen a HD with A before. I even thought of changing it to another letter, just in case.