I don't suppose you have a SATA port you could plug the new drive into somewhere? Here's a question. I assume all of this was done on one computer, using IDE, did you use a single IDE channel (i.e. 1 cable), or did you use two separate ports in your computer (2 IDE cables)?
If you used 1 cable, I assume the old drive was master and the new drive was cable-select or slave during the copy (master/slave/cs should be set via a jumper on the SATA-to-IDE adapter I assume). With only one drive, you want to make sure the drive is set to master, and that it is on the furthest-connector on the cable.
If you used 2 cables, again, make sure the new drive is set to master on the adapter, then make sure its plugged into the primary IDE port (the one the old drive should have been plugged into).
My thinking is that your motherboard is not booting the harddrive because it isn't looking at it when trying to boot. This often happens because of the drives Master/Slave settings, or IDE1 vs. IDE2 in multi-channel systems.