Recovering from a partition that says NTFS found using backup sector

[jayant0jha]

I had ubuntu 18 and windows 10 installed on a 1TB hard disk.
While I was trying to install ubuntu 20 in place of ubuntu 18, I accidently erased the disk and installed ubuntu 20.04.
I didin't had any important data in ubuntu 18, but in windows partition I had three drives, C, D and E.
By usnig testdisk I was able to find drives D and E in a deeper search and I succesfully copied the content into an external hard drive.
But I was not able to list or find the content of the C drive and I don't remember the exact partition size. I checked the whole list of deeper search but I was not able to list the content of my C drive in any partition.
But what I found was a partition of blocksize=4096, 430 GB / 401 GiB which says NTFS found using backup sector. I am assuming by all the posts that I read and the official documents of testdisk that this partition is the backup of my windows partition. But when I try to list the files of this partition it says Can't open filesystem. Filesystem seems damaged.
Now I see the options I have are

Code: Select all

Use Left/Right Arrow keys to CHANGE partition characteristics:
                P=Primary  D=Deleted

I want to recover the files of my C partition, also it will be best if I can recover my windows 10 OS and can boot into it. I am not able to understand what shall I do next? Do I try to do Backup BS and RebuildBS?
Any help is appreciated. Thanks in advance!

[cgrenier]

Please copy/paste the testdisk.log file content.

[jayant0jha]

https://docs.google.com/document/d/1TLl ... sp=sharing
Log file was too long, so attaching it here.

[jayant0jha]

I am expecting a response here. Please help me @crgenier.