Fix for firmware upgrade on Dell XPS 15

Firmware update from 01.00.07 to 1.2.0 is not permitted. The system is configured to block firmware updates to previous revisions

Sound familiar? I couldn’t install any Dell firmware updates for my XPS 15 due to a rogue prefix ‘0’ in the default factory firmware version ‘01.00.07’ causing the Dell BIOS update tool to think it’s downgrading itself. 😐

Here’s how to fix it.

1. Restart your computer
2. From the DELL logo press the ESC key until the BIOS Settings prompt shows
3. Open the Maintenance > Firmware Downgrade tab
4. Remove the check on Do not allow firmware downgrade
5. Click Apply and then exit BIOS
6. Run the firmware upgrade

That’s it!