0xc0000185
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Microsoft · Windows
A boot failure occurred due to an I/O error. The system cannot read essential boot files from the storage device.
Quick Answer
Error code 0xC0000185 on your Microsoft Windows means: A boot failure occurred due to an I/O error. The system cannot read essential boot files from the storage device.. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Power off the computer completely (hold the power button for 10 seconds). Wait 30 seconds, then power on. Sometimes a full power cycle clears transient I/O errors.
2
If using a desktop, open the case and reseat all SATA data and power cables. Try a different SATA port on the motherboard. For NVMe SSDs, reseat the M.2 drive.
3
Boot from Windows installation media and run Startup Repair (Repair your computer > Troubleshoot > Advanced options > Startup Repair).
4
From the recovery Command Prompt, run chkdsk C: /f /r to scan for and repair bad sectors and file system corruption.
5
Run sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows from the recovery Command Prompt to repair corrupted system files.
6
Check disk health from recovery: Run wmic diskdrive get status (if available) or boot from a Linux live USB and use smartctl to check SMART data.
7
If the drive is failing (bad sectors, SMART errors), the drive needs to be replaced. If possible, clone the drive to a new one using a bootable cloning tool like Clonezilla before it fails completely.
8
If a new drive is needed, perform a fresh Windows installation and restore data from backup.
Pro Tip
This issue typically requires professional diagnosis. Attempting this fix without proper training could cause further problems.
Parts You May Need
SSD/HDD replacement drive
SATA cable
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