To recover or copy data from corrupted windows 10 OS you need a bootable windows USB or CD and a back drive or USB.
1. Insert both bootable and Backup USB and power on your PC
2. Hit F12 for Dell and Enter to Boot menu now selet your bootable windows 10 usb
3.At windows installation Screen press Shit+F10 to enter in CMD
4.Now type Notepad, go to file open
5.Make sure you have selected all files
6. Copy your files and folder and pate it in to USB drive
7. You are done