Hi, thanks for the ideas. Neither of the three data drives that I'm trying to get Windows 7 to recognize were boot devices. In bios, my new replacement HD with Win7 on it is the only active one.
I tried a few more times, hooking them up one at a time and once when I left the startup screen to sit for over 5 minutes it brought up a screen saying that it found a drive but it had to test it. I let it run and it found loads of bad sectors. This was in addition to the old C: drive that wouldn't boot up. So two of my four physical drives had errors at the same time.
I hooked up the other two drives that didn't work before and now they work fine. The (2nd) non-working drive was not hooked up when I was trying to get the OS to recognize either of them so I have no idea why they magically started working.
I'm going to put the one win 7 said was full of errors on another pc to see what it has to say. I eventually managed to get my old system drive to work on that pc long enough to get my latest docs off it. I ran a surface scan to try to fix it and the next morning the drive appeared to have been reformatted. I hope I don't have a HD controller problem.