Well, thanks to all your great input, I just opened 'er up and switched those cables...and it works! :) I asked my son if he had disconnected them for some reason and he said he had disconnected everything. I think he likes wires a little bit too much.
Then the screen resolution was all messed up and he reminded me how to fix it and told me that's because I had a new video card. But it didn't do that before I switched the hard drive cables.
So hmm.....now it's probably gonna blow up or something. But maybe, just maybe...I mean MAYBE I can do a new piece now before long. I mean, I have a whole week before school starts again! :)
Thanks again, all of you! Sure do appreciate your help.