1. Disconnect your external drive, start over and proceed with your Windows installation on your internal hard drive.
2. Once Windows is up and running, plug the external hard drive in. Windows will tell you that the drive is not formatted and do you want to format it now? Do not format the drive
. Just cancel.
3. Download the demo of Active@ Partition Recovery
. Run it and see if it can detect the partition information on the external drive.
4. If it can, purchase it, and recover your partition.
If this doesn't work, post back, there is another program we can try, but it's more complicated.