Disconnect the old 250GB drive completely, power and data cables.
Remove the CMOS battery and unplug the power cable.
Press and hold the power button for 10 seconds or so.
Put the CMOS battery back.
Connect the Power cable.
You should get a CMOS checksum error and a Press F1 to continue, F2 to enter setup. Press F2.
Once there, find the key or selection to load default setup information.
Save and exit.
Go back into CMOS setup and see if the new SATA drive is being seen.
Also set correct date and time, power options, boot priority, etc.
Make sure SATA controllers are enabled (SATA 1, 2, 3, etc).