Factory reset partitions wrong format for windows reinstall

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I was doing a factory reset for an
Dell All In One Inspiron model 3052. I had followed prompts and had installed disc. Then it asked for a second disk.

At that point I knew I was in trouble, There is was no second disc. The person I am helping " my aged mother" has no idea where it is. Even after going through .....

I downloaded OS recovery tool from Dell that allowed me to create an USB file to reinstall windows.

I was concerned the 1/2 installed system might be n issue. I normally smile when I am right, not this time.

The second installation it would not let me install on either of the partition saying " .. the selected disc has a MAR partition table. On eft systems, Windows can only be installed to a GPT...."

It gives several options, deleting ,reformattting and creating new. Please see screenshot.

I am not sure if should reformat and loose what is in partition(s), or delete and create new or ????

I would be greatly appreciated if someone could respond with the right answer.

If any more information is needed please just ask.

Thank You.