I just installed a second hard drive but now when I boot my computer windows wont load unless i enter setup and tell it to boot from my main hard drive. BIOS won't detect this new hard drive and windows cannot detect it either.
I had a computer once that would not boot if a drive was not configured correctly or at least set in a clean state. I had to take the drive out and format it in another system and then reinstall. Is this a new drive or if not, what is its current status as far a formatting?
You didn't mention your knowledge about jumpers which could be the solution.
The jumpers are the most common problem. But There are so may other problems it could be. Like a problem in the bios (try updating or chose it to not auto detect) or a problem with the hard drive itself (are the heads spinning?) or maybe even a cable issue (though rare).