All test passed, boot device not found

[mogass]

My HP Envy x360 randomly showed an error screen after I came back from getting food. The error says a boot device can’t be found and to “please install an operating system on your hard disk” (Hard Disk (3F0)). Literally nothing changed from the time I went and got food and came back and yet this error came up on the screen. I tested every possible test with the system diagnostics which all passed. How do I fix this?

[Kuroi_Kenshi]

Hi @mogass,

Welcome to the HP Support Community!

Thanks for reaching out!

We're thrilled to have the opportunity to assist you and provide a solution.

I get that your HP Envy x360 suddenly threw a Boot Device Not Found (3F0) error even though you barely left it alone long enough to grab food. Let’s go through a few steps to figure out why it thinks its own drive vanished.

Fully power reset the system
– Shut it down, unplug the charger, then hold the power button for 10–15 seconds.
– This clears any weird firmware hiccup that can make the drive invisible.

Check if the SSD/HDD is being detected in BIOS
– Turn it on and immediately tap Esc, then choose F10 BIOS Setup.
– Look under Storage or System Information to see if the internal drive is actually listed.

Make sure the BIOS Boot Mode is correct
– If the system was using UEFI and somehow flipped to Legacy (or vice versa), the bootloader becomes unreadable.
– Set it to UEFI, save, and reboot.

Reseat the SSD (if you're comfortable opening it)
– A loose M.2 SSD can pass every HP diagnostic yet still not present as a boot device.
– Remove the bottom cover, unscrew the SSD, reseat it, and tighten it properly.

Run the HP UEFI diagnostics again but focus on the Storage test
– Even if they passed earlier, re-run the “Component Tests → Storage → Quick Test.”
– If the drive intermittently disconnects, sometimes the second run catches it.

Try booting from a Windows Recovery USB
– If it detects the internal drive during Windows Recovery, the bootloader may just be corrupted.
– Use “Startup Repair” or run “bootrec /fixboot” and “bootrec /rebuildbcd” from Command Prompt.

If BIOS still shows no internal drive
– That means the drive failed in the most dramatic, mid-lunch kind of way.
– The fix is replacing the SSD and reinstalling Windows.

I hope this helps.

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