I changed the SSD on my XPS 15 2-in-1 and was trying to do a clean windows install from an external harddrive. I had to change a few things (Secure boot, thunderbolt configuration) in the BIOS for the setup to run, before that, it said "no bootable device found". After the step in installation when the setup takes 10 seconds to restart, the setup resumes from scratch. In disk selection, I'm seeing the setup files it already installed on the new ssd. In BIOS boot sequence, I'm seeing diskette drive, USB storage, CD/DVD Drive, Onboard NIC in legacy external devices and the old SSD (now uninstalled) on it in UEFI. Is the new SSD not compatible? In system information. under device information/ M.2 PCIe SSD-0 I'm seeing the serial number for the new SSD but its not showing up in boot sequence. There are no errors in diagnosis. What is wrong here?
Yes, it wasn't the old disk. It was the external HDD with windows setup. But I got it to install. SATA configuration set to RAID on default was causing the problem. Had to switch it to AHCI and it worked like it should've.