The 30-Second Fix: Check Your Boot Device
Before you dive into command-line wizardry, do the obvious. I've seen this error pop up because someone bumped the power cord, or the BIOS got confused and tried to boot from a USB stick that wasn't there.
- Restart the PC and mash F2, Del, or Esc (depends on your motherboard) to get into BIOS/UEFI.
- Look for the Boot Order section. Make sure your main hard drive or SSD is listed first. If you see a USB or CD-ROM at the top, change it.
- Save and exit. See if Windows comes up.
Had a client last month whose cat jumped on the case, knocked the USB drive loose, and the BIOS defaulted to network boot. Took me 10 seconds to fix, after a 30-minute phone call. Try this first.
The 5-Minute Fix: Boot Repair from Recovery
If that didn't work, Windows might have a corrupted boot configuration or missing system files. You need the recovery environment.
Get to Windows Recovery Environment (WinRE)
Windows should pop into automatic repair after two failed boots. If it doesn't, you'll need a Windows installation USB (USB stick with Windows setup). Boot from it, then click Repair your computer at the bottom-left corner.
Once you're in the blue-screen menu, go to Troubleshoot > Advanced Options > Command Prompt.
Run Bootrec and SFC
In the command prompt, type these commands one at a time. Hit Enter after each:
bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcdIf bootrec /fixboot gives you an Access Denied error, that's common on newer UEFI systems. Skip it and move on.
After that, run a system file check on the Windows partition. If Windows is on C: in the recovery environment (it usually is, but confirm with dir C:\Windows), type:
sfc /scannow /offbootdir=C:\ /offwindir=C:\WindowsLet it run. This checks all protected system files against the installation media. I've seen this fix the error when a driver update nuked ntoskrnl.exe — the file that error 0xC0000143 specifically complains about.
Reboot. If it works, you're done.
The 15+ Minute Fix: DISM and Manual File Replacement
Still stuck? The corruption is deeper, or the file is straight-up missing. Let's get dirty.
Run DISM
Back in the command prompt (same recovery environment), run DISM to restore the system image health. Use this command:
DISM /Image:C:\ /Cleanup-Image /RestoreHealth /Source:C:\Windows\WinSxSIf that fails because WinSxS is also corrupted, you'll need the install.wim from your Windows USB. Mount your USB (usually D: or E:), then use:
DISM /Image:C:\ /Cleanup-Image /RestoreHealth /Source:D:\sources\install.wim:1 /LimitAccessReplace D: with your USB drive letter. The :1 is typically the Windows edition index (Pro, Home, etc.). If you're not sure, run dism /get-imageinfo /imagefile:D:\sources\install.wim to list them.
Manually Replace the Bad File
If DISM finishes but the error persists, you'll need to grab the specific file from the install.wim. Usually it's ntoskrnl.exe (located in C:\Windows\System32). But the error might say %hs — you'll need to check the exact file. On a working machine, search for %hs is bad or missing in Event Viewer, or just look at the error screen — sometimes it names the file.
To extract a single file from the image:
md C:\temp
xcopy D:\sources\install.wim C:\temp /EActually, that won't work directly. Better to use dism /mount-image. But that's overkill. Here's a faster way: use the sfc with the /offbootdir and /offwindir flags we already did — that's usually enough.
If you're absolutely sure the file is missing (e.g., you see File not found when trying to copy it), then boot from a Linux live USB, mount the Windows partition, and copy the file from a known-good Windows install. But that's a last resort.
Last Resort: In-Place Upgrade
If nothing works, you're looking at an in-place upgrade (reinstall Windows keeping your files). Boot from the installation USB, click Install now, and when it asks for the edition, pick the one you have. On the next screen, choose Upgrade: Install Windows and keep files, settings, and applications. This replaces all system files without touching your data. Takes about 45 minutes but fixes everything.
One more thing: if you're on an older machine with a failing hard drive, no amount of software fixes will help. I had a client with this exact error — we replaced the drive and the error never came back. Run a disk check if you can get to a command prompt:
chkdsk C: /f /rfrom recovery.