Ubuntu Not Booting After BIOS Update or Motherboard Replacement

What's happening

Your Dell XPS or Precision computer with Ubuntu Linux won't start up after one of these events:

• You updated the BIOS
• You reset the BIOS to its original settings
• A technician replaced the motherboard

When you turn on your computer, you see an error message that says "No boot device was found" or something similar.

Why this happens

When any of these changes occur, your computer's BIOS automatically switches a setting called SATA operation to "RAID On." Think of SATA as the system that manages your hard drive connection.

Here's the issue: Ubuntu Linux needs this setting to be "AHCI" (Advanced Host Controller Interface), not "RAID On." When the setting changes to RAID On, Ubuntu can't find your hard drive anymore, which is why your computer won't start.

The good news is that you can easily switch this setting back, and your computer will work normally again.

How to fix it

We'll help you change the SATA setting back to AHCI and make sure Ubuntu can start properly. This takes about 5–10 minutes.

Step 1: Change the SATA setting to AHCI

1. Turn on your computer and immediately press the F2 key repeatedly until the BIOS setup screen appears.
2. Use the arrow keys to go to System Configuration.
3. Select SATA Operation.
4. Change the setting from RAID On to AHCI.
5. Press Apply to save this change.

This allows Ubuntu to detect your hard drive again.

Step 2: Recreate the boot option

Ubuntu uses a special file to start up. After the changes to your BIOS, you need to tell the computer where to find this file.

1. In the BIOS, use the arrow keys to go to General.
2. Select Boot Sequence.
3. Select Add Boot Option.
4. Next to File Name, select the button on the right to open the file browser window.
5. In the Directories section, double-click EFI.
6. Double-click Ubuntu.
7. In the Files section, select shimx64.efi.
   
8. Select OK.
9. In the Boot Option Name field, type UBUNTU (all capital letters work best for clarity).
   
10. Remove any other boot options from the list to make sure Ubuntu is the only one selected.
11. Select Apply, then select OK to save your changes.
12. Select Exit.

Your computer will restart and should now boot into Ubuntu normally.