The BIOS doesn't show my NANO as a boot option
Six common reasons the BIOS misses the NANO at boot, and the fix for each. Most are a single setting change.
in this article
- 1. it’s plugged in but not seated firmly
- 2. USB boot is disabled in the BIOS
- 3. CSM mode is off and the NANO needs UEFI (or vice versa)
- 4. Secure Boot blocks unrecognized signatures
- 5. you have multiple drives and the BIOS only lists “Boot Drive” generically
- 6. an outdated BIOS doesn’t detect the drive
- still not showing up
You’ve installed the NANO, restarted, entered the BIOS, and the boot order menu doesn’t list it. Frustrating, but almost always fixable. Six causes account for nearly every report we see.
Work through them in order. After each change, save BIOS settings and reboot to check whether the NANO appears.
1. it’s plugged in but not seated firmly
Power down completely. Unplug the NANO and reseat it firmly in a USB 3.0 port on the back of your PC (back-panel ports are more reliable than front-panel ones). Power back on.
For USB NANOs: try a different USB 3.0 port. Front-panel ports can be wired through unreliable internal cables on some cases. The blue USB 3.0 ports on the back of your motherboard are the most reliable.
2. USB boot is disabled in the BIOS
For USB NANOs only. Some BIOS configurations disable boot from USB by default. Find the Boot or Boot Options section and look for an entry like “USB Boot Support” or “Boot from USB Devices”. Set it to Enabled.
The exact location and name vary by motherboard manufacturer.
3. CSM mode is off and the NANO needs UEFI (or vice versa)
The YOM Node OS supports both legacy and UEFI boot, but your BIOS needs to be configured for one mode at a time. If your boot order shows only “UEFI: XYZ” entries with no NANO, try toggling CSM (Compatibility Support Module) or Legacy Boot on. If your boot order shows only “Legacy: XYZ” entries, try the opposite.
Some BIOSes also have a setting called Boot Mode with options like “UEFI”, “Legacy”, or “UEFI + Legacy”. Set to “UEFI + Legacy” if available, which accepts both.
4. Secure Boot blocks unrecognized signatures
The NANO is signed and works with Secure Boot enabled, but only if your BIOS recognizes the YOM signing key. On some motherboards (especially older ones), the YOM key isn’t preloaded.
Two options:
- Leave Secure Boot on and load the YOM key: in Secure Boot Keys management, set the BIOS to allow custom keys, then the NANO will appear on next boot.
- Disable Secure Boot temporarily: simpler. The NANO works fine with Secure Boot off. You can re-enable it once you’ve confirmed the rest of the setup works and added the YOM key.
5. you have multiple drives and the BIOS only lists “Boot Drive” generically
Many BIOSes group SSDs under a single “Boot Drive Order” with vague labels like “P0 SATA SSD” or “M.2_1 SSD”. Step into the submenu and you’ll usually see the actual drive names there. The NANO shows up as something like “YOM” or the underlying SSD model number.
If that submenu doesn’t list the NANO at all, the BIOS isn’t detecting the hardware. Go back to step 1.
6. an outdated BIOS doesn’t detect the drive
Rare, but possible on older boards: a dated BIOS can fail to enumerate USB boot devices correctly. Check your motherboard manufacturer’s site for a BIOS update. Updating BIOS firmware is a careful operation, follow the manufacturer’s instructions exactly.
still not showing up
If you’ve worked through all six and the NANO still doesn’t appear, contact us with:
- The exact motherboard make and model
- Your current BIOS version (shown on the BIOS main screen)
- A photo of your BIOS boot order screen
We have hardware compatibility data and can usually identify what’s specific to your board.