What is 0xc0000034?
0xc0000034 is a critical-severity Windows operating system problem. The Windows boot loader file (winload.efi) is missing, corrupt, or unreadable, preventing the operating system from booting. It's also often linked to failing storage drive sectors. See the troubleshooting steps below for the fix.
Common Causes
- Corrupted BCD boot configuration database
- Failing storage drive sectors
- Interrupted Windows Update
Step-by-Step Fix Guide
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1
Run Startup Repair via Windows Installation USB
Run Startup Repair via Windows Installation USB is the first thing worth trying, since it resolves 0xc0000034 for most affected systems.
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2
Rebuild the BCD store using bootrec
If the problem isn't fully resolved yet, the remaining steps rule out the less frequent windows instability triggers.
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3
Run SFC and CHKDSK in Recovery Command Prompt
"Run SFC and CHKDSK in Recovery Command Prompt" is the next step worth ruling out for 0xc0000034.
Commands & Diagnostics
bootrec /rebuildbcd
sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows
Frequently Asked Questions
The leading cause of 0xc0000034 is corrupted BCD boot configuration database, though failing storage drive sectors and interrupted Windows Update also show up in our reports.
Most 0xc0000034 reports resolve after "Run Startup Repair via Windows Installation USB". The rest of the guide above is there for the cases that don't.
Treat 0xc0000034 as urgent — it's flagged critical severity, meaning repeated occurrences risk data loss or hardware damage.
You shouldn't need to. Work through the guide above first — a reinstall is only worth considering if none of those steps help.
Sometimes. Microsoft regularly releases patches that fix known BSOD triggers including 0xc0000034. Make sure Windows is fully up to date via Settings → Windows Update before attempting more advanced fixes.
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