Windows Boot Device Not Found 3F0 Error Fix

Boot device not found, or a 3F0 error, is one of the most common problems faced by computer users, especially on older laptops. It usually occurs very suddenly and completely unexpectedly, with the device working well one day, and stuck on a boot error screen the next.

Thankfully there is a proven set of steps, that most users will be able to perform, that will fix the problem in many cases.

Learning More About the Error

The error message will almost always be displayed with one of the following additional bits of information:

  • Please install an operating system on your hard disk
  • Insert boot disk and press any key
  • Hard disk (3F0)
  • No boot device is available

This boot errors occurs when the internal hard disk stops supporting the system boot process. Windows simply can’t find a bootable device to boot from. The reason for this could be that the boot order in BIOS has changed, it could be because there is a connection problem between the hard disk and motherboard, or some of the boot files (or system files that control boot) have been damaged or corrupted. It could occasionally mean that the MBR (Master Boot Record) is damaged.

The problem is, that several of these error reasons can result in the same error message, making it hard to diagnose with a glance at the additional information. It is therefore best to run through the possible fixes in the order shown below.

Fix 1 – Perform a Hard Reset

Performing a hard reset of your laptop can sometimes fix the connection between BIOS and the disk hardware, and as it is easy to do, should be the first thing you try.

Turn the laptop off and unplug the AC adaptor. If your laptop has a removable battery, you can remove this as well. Now press and hold the power button for around 15 seconds to drain any remaining power.

Replace the battery and plug the AC adaptor back in, and then press the power button to restart the PC. Hopefully you will see a Safe Mode screen, where you can choose to “Start Windows normally” and then press Enter.

Fix 2 – Check and Reset the BIOS

The next thing to check are the BIOS settings are correct, and if they are, try resetting them to the defaults. The first thing you want to check is that the boot order in BIOS has not somehow changed.

Turn your laptop off and then press the power button to start it up again. Immediately tap the F10 key to initiate the BOIS management screen.


On the BIOS screen, scroll to the System configuration tab, and then check the boot order. The laptop’s hard disk should be listed first. If it isn’t, follow the instructions to change the order.

Alternatively, you can just reset the BIOS default settings (if you have made many changes to the BIOS in the past, you may not want to do this. Most people won’t even have changed BIOS settings). To do this, press F9, and choose the “Load default settings” option. Then press F10 and “Save changes and exit”.

Your computer should now restart, and hopefully you have fixed the problem.

Fix 3 – Check the Hard Disk Connection

Not everyone will feel comfortable doing this, but you can try opening up your laptop and disconnecting and reconnecting the actual hard disk (this might be a flat cable, or the hard disk might be connected directly to the motherboard).

Obviously you need to be extremely careful when you do this. The process is a lot easier if you have a laptop which has a separate access point for the hard disk, but most laptops now have a single piece case, meaning you have to open the whole thing up.

Take care when opening up a laptop. Unplug it from the mains and remove any peripherals. Press and hold the power button for at least 15 seconds to discharge any stored power. Ideally, you should work on a static dissipative surface such as a conductive foam pad, or wear a ESD wrist strap connected to a grounded surface, to avoif electrostatic discharge from damaging components.

When you have the case open, identify the hard disk and carefully disconnect and reconnect it, making sure the cable is firmly in place. Reassemble the case, and then plug the laptop in and power it up to see if this has fixed the problem.

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Russ Ware

Russ has been testing, reviewing and writing guides for tech since the heady days of Windows 95 and the Sega Saturn. A self-confessed (and proud) geek about all things tech, if it has LED's, a screen, beeps or has source code, Russ will want to master it (and very likely take it apart to see how it works...)

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