"Fatal Device Hardware Error": What It Means and What to Do

“The request failed due to a fatal device hardware error.” Windows shows this when it sends a command to a drive and the drive, or the hardware between it and the computer, reports that it couldn’t carry it out. You might see it when opening the drive, copying files, running chkdsk, or trying to initialize the disk. Sometimes it appears with the code 0x800701E3. Unlike many Windows errors, this one usually means exactly what it says: something in the hardware has failed. Here’s how to find out what, and how to avoid making it worse.

What causes “the request failed due to a fatal device hardware error”

In rough order of how often they turn out to be the cause:

• The drive itself is failing. Bad sectors, weak read heads, or worn flash memory mean the drive can’t complete a read or write.
• A failing USB bridge board. External drives have a small circuit board that translates USB to the drive’s internal interface. When it fails, Windows gets garbled or failed responses even if the disk inside is fine.
• The cable, port, or power. A damaged cable, a worn port, or not enough power from a hub or front-panel port can cause the same error.
• Driver problems, which are less common for this message.

The fact that Windows calls it “fatal” doesn’t mean the data is lost. It means the request failed. What you do next has a big effect on whether the data comes back.

Step 1: If you can still see files, copy them now

If the drive opens at all, even slowly or partially, copy your most important files to another drive first. Don’t start with the biggest folder. Start with what matters most, in case the drive gets worse while you work. If a file fails to copy, skip it and move on.

Step 2: Rule out the connection

These steps are safe for your data and quick to try:

1. Use a different cable. USB cables fail more often than people expect.
2. Plug directly into a rear USB port on a desktop, or a port on the laptop itself, with no hub or dock.
3. For desktop external drives with a power adapter, make sure it’s plugged in and the drive is getting power.
4. Try another computer. If the error follows the drive, it’s the drive or its enclosure.
5. For an internal drive, reseat or replace the SATA data and power cables.

If the drive keeps disconnecting and reconnecting, treat that as a warning sign rather than a nuisance.

Step 3: Check the drive’s health

Use a SMART tool to see what the drive reports about itself. Our CrystalDiskInfo guide explains how to read the results. Look for:

• Reallocated Sectors Count, Current Pending Sector Count, and Uncorrectable Sector Count above zero: the drive is developing bad sectors.
• UltraDMA CRC Error Count rising: this points at the cable or bridge rather than the disk.
• A status of Caution or Bad.

Some USB enclosures don’t pass SMART data through, so a blank result doesn’t prove anything either way. Our guide on how to check hard drive health covers other ways to check.

Step 4: Don’t run chkdsk /r, format, or initialize

When a drive is failing, the usual “fix it” tools make things worse:

• chkdsk /r scans every sector and tries to relocate bad ones. On a drive with weak heads or spreading bad sectors, that’s hours of extra stress, and the repairs it writes can make files harder to recover.
• Formatting replaces the file system, and a full format overwrites the data.
• Initializing a disk that shows as “Not Initialized” writes a new partition table over the old one.

If Windows prompts you to format or initialize the drive, cancel.

Step 5: Image the drive before any repair

If the drive is readable but degrading, the safest approach is to make a sector-by-sector copy (an image) onto a healthy drive, then work from the copy. Tools like GNU ddrescue on Linux are designed for this. They read the easy areas first and come back to the damaged ones, instead of grinding on a bad spot:

sudo ddrescue -n /dev/sdX /mnt/backup/drive.img /mnt/backup/drive.map

Here /dev/sdX is the failing drive and the image goes onto a separate, healthy drive with at least as much free space as the failing drive’s full capacity. Getting the source and destination the wrong way round destroys the data, so only do this if you’re comfortable identifying drives on the command line. If the drive is making noise, skip imaging and stop.

The external-drive caveat

If the bridge board has failed, the obvious move is to take the bare drive out of its case and connect it directly. On many externals, that doesn’t work:

• Many Western Digital external drives encrypt data in hardware on the bridge board, even if you never set a password. Removed from its case, the drive reads as gibberish.
• Many portable drives have the USB connector built into the drive’s own circuit board, so there’s no standard connector to plug into.

For these drives, a bridge failure needs a lab that can deal with the electronics without losing access to the data.

When to stop and send it in

Power the drive down and stop troubleshooting if:

• It clicks, beeps, grinds, or doesn’t spin up.
• The error appears after a drop.
• The error follows the drive across different cables and computers.
• SMART shows pending or uncorrectable sectors that are climbing.
• You also see I/O device errors or CRC errors on the same drive.

A mechanically failing drive can lose recoverable data with every extra power-on.

The bottom line

“The request failed due to a fatal device hardware error” usually means the drive or its USB bridge is failing, though a bad cable or port can cause it too. Copy important files while you can, rule out the connection, check SMART, and don’t run chkdsk /r, format, or initialize. If the drive is degrading, image it before trying any repair, and if it’s making noise, stop.

If the drive won’t cooperate, our external hard drive recovery service handles failing disks, dead bridge boards, and hardware-encrypted externals for one flat $1,200 price per single device, with free prepaid shipping, and you pay nothing unless the recovery succeeds.