You need not have two partitions. ( I had two and hence it showed two) If you had followed the steps correctly TestDisk should show the full drive (one single partition in your case) - the seventh Window in Part 1 of my write up. You will select that only partition press Enter and in the eighth Window select write and enter. That will write the partition table.
Other than that do not enter any command like add partition etc.,. You could have gone astray somewhere. Press Quit, Quit and Quit till you get out, or close the window, start again and repeat the steps carefully.
Fiirst, second, third and fourth Window in Part 1, fifth, sixth, and seventh Window in part 2 should be the sequence.
For the sake of clarity, I shall list the screens again in brief - which itself is going to be long and I had to rerun Test Disk many times to get a grip again.

:
Run Test Disk as an administrator
First Screen: No Log > Enter
Second Screen: Select your external drive > Proceed > Enter
Third Screen : INTEL > Enter
Fourth Screen: Analyse > Enter
Fifth Screen: Here I envisage three possibilities.
a. Your single partition is shown with an * prefix (Test Disk has already found a bootable
partition)
b. Your single partition is shown (without any prefix ) and the message
No partition is bootable
c. Only the message
No partition is bootable
Irrespective of what is shown on this screen, (select the partition if shown) Quick Search > Enter
Sixth Screen: If you do get this screen it will be "Partition created by Vista or Later?" Press Y
If you do not get this screen, you will straight away get the seventh screen.
Seventh Screen: Your single partition should show up with an * prefixed. It should also say "Structure OK .............. Keys: A - add partition L- load backup...... P - list files Enter to continue."
You will only press Enter.
Eighth Screen: Write > Enter.
This will write the partition table and you will be asked to reboot. Hopefully your drive should be readable in Windows.
If in the seventh screen you type P then it will list all the files in the partition which you may be able to copy to another external drive. ( For this you must have connected another external drive before you started this process. Rerun Test Disk and do it.) I had done this when I did the trial, but cannot recollect the screens now. It is very hard to remember. You have to read each screen and do accordingly. If you have any doubts read the documentation on the Test Disk website and try to understand as much as possible.
You can repeat this procedure any number of times as long as you take care not to give any other write command except the Write Partition table command in the seventh screen.