Ubuntu on Dell XPS 9520
Before installing Ubuntu:
- For dual boot, disable Bitlocker in Windows
- Update BIOS (and everything else that Dell recommends) via Windows
- Switch from RAID to AHCI in Bios
- Use Windows recovery to fix new disk setup
- Disable Fast Startup in Windows
- Disable secure boot in BIOS (or make sure it's disabled)
- Shrink main partition in Windows