First of all I want to thank everyone for checking out my thread and especially to those who post help here. Here's my problem. I have a Compaq Presario 7xx laptop that I built from parts. It won't boot past the Compaq screen, it just goes to a black screen with a cursor in the upper left corner. The light on the keyboard shows that the HD is working, but nothing ever happens. If I put the HD from my working 700 in, it does the same but says 'operating system not found'. I used my restore disks to restore the first drive in the good computer so I know it works, but the computer fails to see it or something. This is my second MB in this computer. The first one did the same thing. Starting to think it's not the MB! Could it be the little board that goes from the MB to the battery/HD? Is this a software problem? Any help would be greatly appreciated as I am pretty dumb when it comes to computers. I just have the ability to put things together like a 3D puzzle.