Orig:  https://www.dell.com/community/Windows-10/Purple-Dell-OEM-Windows-10-Pro-64-bit-disc-can-t-clean-install/td-p/4780029

RE: Purple Dell OEM Windows 10 Pro 64 bit disc, can't clean install?

Very similar to issue I ran into possibly.

It is not as simple as it used to be because of the new UEFI BIOS.

Here is what I got from Dell...

How to Install Windows 10 from a Dell Windows 10 DVD

Look in BIOS , if shipped with W7 it is most likely in Legacy mode

1. Boot from the DVD (F12 Menu) (Legacy Option > DVD)

Note: You may experience a delay (1 to 5 minutes) to boot to the Dell Screen with Spinning Circles.

2. Choose English

3. Choose US

4. Choose Troubleshoot

5. Choose Advanced

6. Choose Command prompt

7. In the Command Prompt Window, enter the Command: "diskpart" > Enter

8. Next Command: "list disk"

9. Then: "select disk 0" (0 being the hard drive where the OS should be installed if there are multiple drives)

10. Type "clean"

11. Type "convert GPT"

12. Type "exit" (2 times)

13. Power down the System

14. Restart the system tapping F12 for the BIOS

15. Change the Boot List Option from Legacy to UEFI with Legacy Option ROMS "Enabled"

16. Navigate to Exit and "Exit Saving Changes"

17. Reboot F12

18. Choose UEFI DVD boot option

19. Dell Screen

20. Note: You may experience a delay (1 to 5 minutes) to boot to the Dell Screen with Spinning Circles.

21. Choose English

22. Choose US

23. Choose Troubleshoot

24. Choose Recover from a drive

25. Choose either "Just remove my files"� or "Fully clean drive "

26. Dell screen - will show recovering this PC XX%�

27. Reboots to W10 when finished