Open Disk Management by pressing Win Key + X. Make sure you select the external drive, highlight it and use the menu in Disk Management. Try deleting the F partition first and extend the main partition instead of reformatting. That should work. If that doesn't work reformat the drive.
That was an easy mistake to make since when you make a recovery disk. "Everything will be deleted." warning can be overlooked. Norton had nothing to do with it. To make a recovery drive, use a usb thumb drive and test it afterwards. Some thumb drives don't work correctly.